Hi there,
as an passionate player FF, i like to build slightly larger city (1500 to 2000 residents). But if you play up to 400 years a longer, you need to have a lot of crypt"s which are limited to 2000 corpses. This requirement is annoying. Because i like to build a city for the living not for the death.
The Solution are Catacombs (like in Paris) with an infinitely space for deceased residents by ultra long plays like the infinite deep mines.
Please think about 
kind regards Paul
I too enjoy building larger towns. My highest population to date is over 2,800 citizens.
Personally, once I have exhausted all the buildings and knowledge tree advances and built all the memorials, there is not much left to do. I can’t imagine having the same town for 400 years. I think my longest was 90.
I’ve never had my graveyard and mausoleum become full, but if so I can always build another.
The loghorrean thanks you
I actually think this is a super fun idea. Maybe we have to place the entrance somewhere near a cemetery/crypt and it has a bit of a spooky medieval ossuary aesthetic. The downside is it could introduce some risks associated with having them, such as citizens getting lost and dying down there.