I love a good corset, so I was left a little vexed when I asked myself the same question re blood-clotting.
I think even the most pro-corset websites will warn you of the dangers of tight corsetting, waist-training etc., irrespective of whether you are taking or not taking hormones. I imagine that there is some extra risk involved if you are on hormones. At least, to be safe, that's the assumption that I'm making.