I always used Cuberite with enforced 1.14 as test server worked.

But both your points are valid, doors are implemented like shit in < 1.13, but I added support https://gitlab.bixilon.de/bixilon/minosoft/-/commit/9afbe0df... (Oct 14, 2023). I will test that...when I got time :)

No clue about mobs, but textures were named differently back then. Could be.