Oooh stays! Just to add more options to your list, you could also go with elastic stays. Those are super comfortable and easy to pattern. Those Bernhardt ones are fascinating! I gave that a try once, but didn't have much success with fitting the bust gussets. Those are always tricky for me. There are a couple in Jill Salen's corset book that seem to be 1790s. Do you have that book? I'm thinking of these stays in particular: https://thedreamstress.com/2019/06/the-quest-for-regency-uplift-achievement-unlocked/ I think the nice thing about stays in this period is that they are pretty quick to put together. Good luck!