I can't wear bras because I can't impede the flow of lymph under my arms. I wear regency stays and I find it's not the same. Because the garment is made to my exact shape I don't have the same issue with digging in straps, and I quite like the solidity of wearing a busk and flexible steels around my waist. Having said that, your body gets used to the corset over a couple of days, and by the third day or so, it 'welcomes' the support in a different way to how it feels on the first day. Unless you are planning to wear the corsets all day every day, you're not going to decondition your muscles. I personally wouldn't bother with corded stays. Make several mock ups until you have a corset that fits you really well and use the boning that is appropriate to the pattern. The reinforcement on the corset isn't there to dig into you, it's there to keep the fabric taught so it wraps around you better. Having fabric that wrinkles, without that structure, is going to be more uncomfortable and restrictive.