Hi!
Is it possible somewhere in the minitaur setup to reduce the range of the instrument? I.e. don’t want it to respond to midi notes above a certain value (I want to use only the bottom half of a midi keyboard to play bass, while using the top half to control other sounds.
Thanks a lot 
No.
And I non of my synths got such a function, unless is features some multitimbral options.
That’s what MIDI controllers are supposed to do. And just because a keyboard can output MIDI doesn’t make it a “MIDI controller”, it may not have split functions. I sold a digital piano because its capability as a MIDI controller were woefully inadequate.
no, it’s not possible. You should try a digital piano.