I'm not sure what it the main cause of the slow updates, i doubt it's processing power. With the amount of Patreon subs he has, he can easily get a monster PC with two 4090's, I'm sure he would also prefer things rendered faster for his thought process.
DPC is very talented, based on his two games, writing, music and art direction is top tier.
Maybe the slowness is coming from the vast amount of ingenuity and new mechanisms, i would guess that at this point, probably 95% of players world prefer he drops most things the are supplemental, such as: special renders, rewards, PACK, and especially the new elaborate mechanisms like mansion fixing, jobs, and now evidently party planning. I WISH he would do that.
But, like i said i think he is extremely talented and probably has his own process he won't deviate from.