Have to admit, my first impression was not great. Mostly because I think the example dress is terrible, from the materials to the quality of construction. I'll admit I hate pastels, so someone else may feel differently. The underskirt is pretty boring and steampunk-standard. I really love the back of the jacket, but the weird front that seems to be trying to do a 1910's style looks really odd to me. Of course the bustle cage is cool, but I wonder how practical it is, attached only at the waist. The ruffles are apparently "raw edge finish" which I personally dislike because so few fabrics really look good that way. It also feels lazy in a pattern, IMO.
Butterick has released this Downtown Abbey-esque pattern, which I feel a bit "meh" about.
Vogue has this interesting dress, which I feel could be a good base for casual steampunk.
Simplicity has a couple interesting offerings.
They seem to be making a more serious attempt at a real corset pattern. The front of the pattern tells you all the details of their corset that are good. Like steel boning and busk and back lacing. They include different cup sizes, but apparently some only have boning going to the underbust? But both drawings appear to be a cupped corset with no boning in the cups? I'm confused.
But okay, the cups might actually be useful for a cupped corset. But the corset still appears to mostly just stop at the waist. The actual photos look better than the line drawings, which look like bustiers. But there's still not much waist-to-hip curve, which means anyone with natural curve will find this uncomfortable or won't actually get any waist cinching. Plus it's very short, so really more appropriate as the top of a dress, as it's shown here.
I don't know. This might be fun to play with, but I think it would require a lot of modification before really being good. I also wonder if they've stopped adding ease to corset patterns yet. If not, you'd still need to automatically go down two sizes from what their chart recommends.
Finally, Simplicity has this AWESOME vintage dress pattern. I swear one of these months I'm going to make myself a 50's dress and I keep changing my mind about which pattern I will use. Not steampunk, of course, but still. Plus, plus sizes!