Hi, do you know when you will be adding flatchest blendshape to the clothing?
I'm afraid i don't currently have plans to do so. To be honest, the flat chest blendshape on the body got left in there from early testing, it wasn't an intended feature in the published version. My sense from working with it was that I wasn't satisfied with the flat chest for a "masculine" option- the shading and topology still felt like breasts, and the breasts returned as soon as any level of weight gain or feeding blendshapes were applied. So I abandoned the option and committed to doing strictly feminine shapes.
That said, better support for flat chest/ masculine shapes is one of the more popular requests I've gotten, so it's on my radar as something that a lot of people would like, and I might revisit it down the line.