what is the untempered schism supposed to do because it doesnt do anything.

It is a decoration block. In doctor who timelords look into it and that is what gives them their regenerations, it was gonna do the same in dmu, but the Devs thought it would be to OP

If you enable BOTI it shows really cool vortexes

will the mod devs add a config setting to enable/disable the untempered schisms regeneration gain feature?

or is it just for decoration now?

In single player it should work I believe, also it might say on the Dalek Mod wiki

i can't find anything in the mods changelog saying its been disabled