I have to admit that I am ahead of you guys
I had two ways to make people crazed, one is transforming them into a custom creature that is a dwarf copy, non-civ member and crazed, the other was by syndrome, adding the crazed tag. To make it more obvious who is affected, I added the display name "maniac" I thought the second way would work better, since it does not require a transformation, but making people crazed with a custom reaction does not revoke their civ-membership. Someone mentioned that once in the modding forum, but so far I never got a report about the loyality cascade happening.
When you said this, I immediatly thought about all this, that is why my first question was exactly about it.
tl;dr: I know the bug. And I know how to fix it (by using the more complicated version with transformations) I just never like using transformations to often, because of the random-crashes when viewing the creature description (conflicting colormodifiers) AND that there will be no dwarven corpse to bury. (maybe, transformations should revert back to normal after death, but itemcorpse and similar things overrides this)
But Thanks
One more obscure bug found. A rare one as well. Next research reactions will be different.
Edit: Wait a second, that is exactly what I wanted this succession fort for in the first place
Everything went better then expected