Huh. It's been some hours since the Map went up and no comments. I suppose that for many of us, as in my case, this is largely because actually your text description of the situation was clear enough that we could pretty well visualize this map. It is very nice to have the map, since it clarifies the exact territories at a glance, but for China's situation there are no surprises, once we've read the text.
So, regarding China itself I have just one remark--Beiqing looks awfully vulnerable to Russia.
This may be an illusion, due to the thin presence of Russians in the Far East; behind that vast and encircling border for the most part Siberia is the The Big Empty, whereas Beiqing is the ancient core of China, highly populous and developed.
But Russian possession of Yapon and alliance with Corea, whatever that latter means, makes the situation much grimmer for Beiqing than OTL at Russia's maximum expansion. It depends on how closely aligned these territories are with Russian ambitions; if Corea is a very loose ally of convenience, the Russians have to walk softly, especially if Yapon is in any way difficult to hold due to fractious rebelliousness. The Coreans probably are at the very least wary of letting further Russian advances encircle them.
Some readers seemed to think for Corea to ally with Russia at all at this stages foreshadows their eventual swallowing up in the empire, and it certainly might.
The Feng are also rather beleaguered, but the powers closely surrounding them are more divided; four Asian powers, none of them closely aligned with European allies, are the main threat on land, and Hainan and Taiwan are indicated to belong to European powers.
(The main improvements to the map I would suggest would be to at least indicate the location and names of the capital cities, and to clarify which European powers hold which islands. I seem to recall Taiwan (called Formosa by Europeans at this point still) was Dutch but the Dutch have been expelled and now it's some sort of co-dominium of a committee of other European powers).
By elimination, I gather Meridian, that is, unless my LTTW memories are very confused and rusty, the USPA, holds the Philippines, or at least Luzon, whose northern extremity shows on the map. I vaguely recall some shenanigans going on regarding who holds those islands resulting from the Spanish reorganization, the formation of the new federal kingdoms in America, and even--very vaguely!--a Meridian expedition in the course of one of USPA's wars with this federal empire that seized the Philippines, from I believe Portugal, which had assumed the islands from their puppet-Spain.
So now my nitpicking the map leads me pretty much off it completely and out of China too, into yet more "update! update! we wanna know more about X!" Where X is, the Meridian regime in the Philippines!
How does that work out?
OTL, the Spanish were able to hold the islands with a relatively small investment of force; their major problem was to deter other European powers from trying to seize some or all of them, and that didn't always work--the British held Manila and perhaps at least nominally all of Luzon for some time in the 18th century I believe. And of course in the end the islands were taken by a predatory Great Power on the make.
But there was also internal unrest to consider; originally getting loose control over the archipelago was helped by the fact that the peoples of the Philippines were in no sense closely united; I believe there are more than 5 major language groups on just Luzon alone, or something like that. It was mostly accomplished with missionaries, by mainly a process of persuasion that gradually gave the Spanish enough native auxiliary forces so that rebellion in one region could be put down with soldiers from another. And realizing the weakness of their position, and the great distance to Spain (Spanish communications went via Mexico and across the Pacific, since the other route through the Indian Ocean was deemed Portugal's assigned hemisphere by the Treaty of Tordesillas) they did not seek to unify the islands, or impose Spanish language or culture, because the fragmentation of the native peoples remained a mainstay of administration. Numerous missionary orders, each specializing in a particular language group, remained the priesthood (and most of imperial authority) for centuries; they did not teach their "flocks" Spanish for the most part, nor recruit natives into the priesthood.
Still gradually some shared culture of being islanders together versus the Spanish did develop, largely organized around syncretic religious movements; these could lead to major rebellions that were quite hard to suppress.
So what I'm wondering is, how the Meridians have found the situation and what they are doing about it?
First of all all the upheaval, with Manila being tossed from one rival Iberian claimant to another, must have agitated the more marginally peaceful communities, perhaps inspired yet another charismatic prophet-leader to come forward in the countryside.
Then in come the Meridians, this timeline's real analogs of the USA of OTL. But different--the USPA is a federal union not only of a bunch of immigrants from Europe, but also native peoples--from small tribes to big empires. Ideologically they are democrats and champions of the common man.
This could lead to the Filipinos spinning completely out of control as they take the ball and run with it--it might even have something to do with the rise of Societiesm in USPA, if there is a colonial fiasco.
But maybe the Meridian ideology works to encourage the Filipinos to adhere to the union, as respected partners of a diverse federal state?
This question was orginally prompted by seeing Meridian mentioned on the China map, and wondering just how much access USPA has to China. If the Philippines are a distant and very doubtfully held territory for them, they wouldn't have much. But if the Philippines are evolving into an integral USPA territory, with its peoples coming around to ideological commitment to membership in USPA, the islands can indeed be a springboard for major interventions.
That after all is what the Spanish hoped when they first made the effort to incorporate the place way back in the 16th century--a channel to China. And that was part of what Americans hoped to get out of the place when they took it from Spain just before the 20th century. Few conquerors would be moved to make the effort to seize the archipelago on its own merits, they were generally thinking of its strategic location, with an eye to further conquests of one sort or another.
I'd have to go back and read why the USPA took Luzon in the first place to have a better clue what is likely going on the minds of Meridians today, but some kind of imperial/mechantile adventure does not seem out of bounds.
Regardless of the state of Meridian/Filipino relations, these ambitions may still have been behind it and might hold even if the Philippine countryside is currently wracked with quasi-religious rebellions. But they are likely to be much stronger if the Filipinos are coming around to identifying with Meridian.
And a successfully assimilated Philippines might also be the basis of the rise of Societism in USPA; Meridian society already has some expertise in being a meta-society incorporating many languages and distinct peoples, swallowing up the Philippines will strongly extend that flexibility and underscore the point that despite differences in appearance and language and custom, people are one. Whether further adventures into China or other territories are rebuffed, or successful, the USPA approach to overseas empire might be much more oriented toward co-option and recruitment of diverse peoples, on a bottom-up model--no treaties or deals with local princes, instead champion democratic revolution against all established powers, and then foster a new republic to join USPA as a new state.