We are doing a trial of ALEKS and many/most of the problems have to be copied onto scratch paper in order to solve them. DS is in the middle of third grade on ALEKS. I don't know what the higher levels are like. So in a way, it is even worse than a worksheet where the problems are already there and the answers just need to be written.
That's definitely a ymmv thing then - I was always trying to get DS to write things down, but he never would, and just solved everything in his head (with more exceptions creeping in in later courses, but I mean much later). Might be worth doing a trial to see how your DS finds it, OP.
