You are right that both China and Russia are clear eyed about America’s totally transparent intentions with their latest ‘peace’ talks. However, it’s actually entirely possible, advantageous even, for Russia to go along with it if it can secure the necessary concessions from the Americans.
The primary reason would be that America and Ukraine won’t be the only ones who can take advantage of the ensuing pause in the conflict to rearm and resupply.
Russia is already winning the logistics war against America and the rest of NATO with no direct military imports from China. How do you think the re-arm race will go when China full-sends military exports to Russia after a ceasefire is agreed?
Russia is achieving a favourable KD ratio right now, but there are fundamental issues with its war machine that is hard, if not impossible to fix while they are in a full scale war and China isn’t willing to sell arms to a participant in active combat. But with a pause in the fighting and the full catalogue of Chinese arms unlocked, Russia can fundamentally revamp its military and give it a quantum leap in a couple of years. Then, when it is ready, it can basically manufacture any pretext it wants to restart the war and achieve far more favourable exchange ratios while also being able to conduct proper combined arms warfare instead of its current grinding attritional slog.