Nope it dont think its acceptable to get 2 updates in 2 years (or one in one year) but i dont think that it will be this way.
DPC started to develop ep 9 in march, late march even... after all we know now, it will be released within the next 6-8 weeks, so overall it will take around 9 months and a little more to finish it...
It will be the biggest episode so far, with the most complex animations so far, and THOSE animations took the majority time to render... in fact, he was pretty much done with the whole episode 3 weeks ago, only the animations and polishing was left to do. And now only the animations are left and the play testing by others...
Its fair to say, he went overboard with the animations, and i think he will realise that.
But... he can upgrade his slaves, buying some RTX 4090 for this will make it much faster to render these animations in the future. So even if ep 10 will be as big as ep 9, the whole rendering will be faster, and you can bet your ass that he will upgrade his hardware, ccause until now, he always did as soon something was available... wouldnt surprise me if he already has some RTX 4090 lying around but just didnt wanted to upgrade during the process.
but if you ask me... ep9 will be the "peak" for the biggest episode, and i would guess ep10 will be around the amount of ep 7 maybe which will be about 30% less than ep9 will get.
All that in mind, i would say its more likely that the next episode will get out faster and will be a little bit smaller than this one, and we will get it in around 6 months...
And looking at the progress numbers... he hasnt slowed down, you can see that by the post of
mpa71 (btw, awesome work)