With satin's propensity for slumping, sliding, and snagging, I'd use either a layer of coutil with boning tape for the strength of the corset, with satin as a fashion-fabric outer layer, or two layers of coutil, boning between, with the fashion fabric overlay. The satin will be very, very warm, so that's a consideration for any summer programming.
Yes, I have been thinking about the slipperiness - it'll be tricky. It's a fairly solid weave, though, so I think it'll be possible.
The heat is a good point! On the other hand, the summer event is just a couple of days and then done. It might end up just being worn for Victorian Strolls around Christmas in the future. (Yes, this is rationalizing for the sake of the Pretty.)
Another option is to skip the satin, but use a nice silk to do some decorative & functional flossing on the corset. You'll get a very pretty look, without the fuss or heat of the silk.
a good option, I'm just not sure I trust myself to actually do the flossing after the rest is finished if I'm not using a nice outer fabric. Bad habits ... Do you think a taffeta would be noticeably cooler? I could always save this satin for a future corset.
I would recommend using the thinnest really stable material you can for the inner layers. My old 1860s corset, made from an ancient Past Pattern kit, was two layers of heavy cotton twill, and I really notice the letup in weight and oppressiveness in my new one. A lot of corsets of this period were actually only ONE layer, a pretty outer being the very distant exception. The vast majority were white or tan sturdy cotton.
(Do you have any pictures of the blue silk corset online? I'd love to see it!) Yes, with each corset I make I'm working at getting rid of assumptions about shaping and engineering and materials - you always start out thinking they need to be bulletproof, and then scale down from there. I think my first was two layers of cotton drill, with a white muslin outer fabric and an unbleached muslin lining, from a Butterick pattern. I didn't realize most corsets of the period were single layer; would one like e.g. this
have boning channels applied on the side closer to the body?
As to shape, I have a very wide, bony pelvis, and I cannot express how much better my new corset with a large hip gore is. SO MUCH BETTER. It makes the whole corset work as it should. I basically patterned it after this patent diagram, except that for me it worked better to end the front gore at the side seam and add a separate back inset as per the V&A example.https://www.pinterest.com/pin/394768723563548628/
I am also using that pattern as a guide (taking out the side seam, because it seems a bit unnecessary)! The shape of the gore was giving me pause, too - it seems like the shorter hip gore with another added in the back is more common. I might try out the Sebille pattern as drawn in the mockup phase and see how it goes.