This will, on top of everything, depend on how crazy (very crazy, from experience) the North Korea guy is. When the Korean War starts, presumably like it did IRL, I'll probably be in the stage of either finishing up mainland KMT or having already finished them and preparing to invade Taiwan (and Hainan, if it hasn't fallen by then). At that point, IRL Mao picked Korea over Taiwan in his priority list.

The strategy tl;dr goes: Taiwan before Korea. At this point the USA doesn't really believe in the survival of the KMT anymore and CPC hasn't properly shown which court and how much they play into, meaning they could be a half-decent partner (if only for trade and whatnot) in East Asia. It's China after all, shit's sought after. CPC can reasonably-logically assume that the USA has more or less given up on protecting the KMT since the latter has lost shatteringly by then, but CPC would remain on high alert for the chance that the USA decides to step between mainland and Taiwan. CPC doesn't rock much of a navy beyond junks and maybe a small amount of modern shit.

So naturally Taiwan is in an "invade ASAP" slot for military planning, but then Korea breaks out, North invades South, US gets involved and USSR really can't get involved too much because it's the aggressor side, it's hard to get troops there, it's direct warfare against USA etc., all of which means CPC would have to bear the brunt of the communist side.

But with sheer political mathematics in mind - we've got 2 enemies. Taiwan, South Korea. What happens if we ditch Taiwan and go into Korea? We might win, we might lose. In the event of a victory (unlikely, since I'm fresh out of civil war and the other side is the fucking USA) or a status quo (likely) we end up with the same situation in Korea (an US ally present, next to our "ally"), our economy further strained, our relations with USA and South Korea and Japan fucked, and Taiwan is presumably lost because suddenly the USA have a reason to protect them. In the event of a loss in this scenario - Taiwan is lost, North Korea is lost, economy strained, relations strained, etc.. Putting Korea before Taiwan is risky and results, at the very least, in a guaranteed gain of USA as an enemy and Taiwan as an independent friend of theirs.

What happens if we postpone getting involved in Korea? We take Taiwan without much of an issue all the while making no significant effort at a military buildup near Korea to avoid any American knee-jerk reaction and potential involvement with Taiwan. Once Taiwan is secured within 4 months tops (estimation based on the real life campaign to take over Hainan, one that I presumably will have conducted by then), buildup can commence, no significant harm done.

Effects of postponing Korea: South Korea might push back NK with US help and regain the entire peninsula. Somewhat likely. In which case we end up with roughly the same situation as before, only the capitalist nation has become slightly larger and now borders us. In a long-term plan, this could be good. USA is far away, whereas I (and you) directly border Korea. A counter-attack for the liberation of NK a few years into the future is not off the table. Neither is loading SK up with Chinese/North Korean infiltrators to start picking on the foundations of the Korean state and fueling a civil war. At the same time, Taiwan has been eliminated as a threat, so in the end a political net gain has been made for China.

There's also the possibility that the Korean War doesn't end or reach a conclusive point while I'm busy invading Taiwan and subsequently building up my forces, in which case I can possibly get involved on a larger scale and prevent a unified capitalist Korea altogether.