I feel like proper weighting, proper training, good fitting suit and "negative" fins are a better option than ankle weights. I can imagine ankle weights cause cramps and increase air consumption, plus are likely to keep you feet down rather than in proper trim.
With proper fit and proper weighting, feet up ascents should not be a big problem.
During my class, I did a few extra dives as I had an uncontrolled ascent which sort of unnerved me. ( plus I felt I needed more experience in cold,dark water. I had a couple of other issues, unrelated to the drysuit, like mask flooding and kelp entanglement, which caused me some worry due to lack of recent cold water experience. Luckily, my husband was my instructor, so he was more than happy to make sure that I was properly trained.
Lots of "experts" think ankle weights are a bad thing. Lets list some of the advantages. They are weight that I don't notice, not on my back, and I just don't feel them underwater. They keep the lower legs and feet of my suit from inflating out. They are remarkably well positioned to help the #1 drysuit problem of unintended feet first ascent.