Built-in autosave feature (for the TE version).

There will be fewer battles, but the number of game days will noticeably increase. No matter how you look at it, it will still take a long time. Indeed, the role of mages will increase.

Overall, the idea with neutrals is interesting.
"-":
1. Simultaneous turn is not applicable.
2. The game will become similar to a game with an open map.
3. The game time will increase.
4. Imbalance may increase due to the layout - archers and fast melee units will become very dangerous.

"+":
1. Neutrals will not be ordinary zombies as they are now.
2. Battle and crypt-taking tactics will change significantly, and there will be no universal tactics.
3. Although the game will take longer and simultaneous turn will not be applicable, it may become interesting throughout, and not just during your turn, because the waiting opponent will be actively involved.

I think it is not difficult to implement this in the current version of the editor. We need to ask the scripting experts, for example, SAG. There are two options here: either it is not difficult to implement and can be done quickly, or it is impossible.
It would be interesting to test such a version.