I caved
I ripped out the front panel I had already whipstitched in and sewed it on the machine just to see what the seam looked like. And it looked so much better. The whipstitch method definitely works well, it's just that my skills are not up to par just yet, and the thread continually breaking and the pain of pushing the needle through all those layers were irritating enough to make me glad that the machine method worked so well. Plus, it's so much faster. The already whipstitched panels have all been ripped out and the whole thing is now sewn together! Well, except straps. It's not a super duper accurate pair of stays anyways, so I feel alright about all the machine stitching. I was going to do the channels by machine anyways. And it's all cotton and the silk is dupioni, so very not accurate, but all the inaccuracies are conscious decisions, not a result of ignorance, so I can always do a good pair if I want. I feel like I'm still in the early learning stage, so making things a bit easier and lower cost makes lots of sense right now. Up next for the stays is eyelets and boning channels.