Only now found this older post. We use variants of questions in our numerical question types too. As Questionmark Perception cannot create dynamic variants on the spot (as for instance Maple TA does), we create all variant questions in Excel and then import them into QMP. Using Excel brings the advantage of being able to fine tune what variables will be used and how. So no ‘ugly’ questions.

It would be interesting for us to use the same approach to try to measure the difficulty of each variant.