I don´t doubt that fixing real issues like the pathfinding bug are more important
. But to be honest, IMHO a lot of changes already change the game experience compared to the original. See, smarter enemy keepers are surely desirable if experienced long-time players need a bigger challenge, but when enemy keepers were pretty dumb in the original game, well, then it is how it is.
Also the grenade spell is one of the mightier ones in the game. It was already pretty devastating in possession mode.
Giving the option to enable and disable some changes via the launcher would be also good for some changes that not all might want. E.G. I´m not the biggest fan of the bigger dots on the minimap(I had no issues with the original mini dots). Or that some bugs like the claiming neutral creatures through diagonal rifts and digging through neutral walls in possession mode were fixed - because in 99 % of the levels they aren´t problemativ but in 1 % they make them unsolvable(see the moon level of the Arctic campaign) or more annoying to solve(in Morkardar I don´t desire to play it again in a "normal" way when I rushed it with Horny).
Don´t get me wrong, I appreciate the work of the devs to improve the Dungeon Keeper gameplay, but for some changes it is debatable if these are desired. Therefore I´m not that lucky that when installing an alpha build I have some changes that are ok, but others not. Just my 2 cents.