Transpose (mostly) behaves in the expected way: ie if it says -12 and you type -14 it changes to that, but tempo adds to the number (eg if tempo is 120 and I type 100 it adds it, to a max of 360). I’ve been caught out often, hitting play and finding it’s 360 BPM.
Earlier versions of Cubase (I’m talking V3) were more consistent. A small point, but it makes the program look unfinished.