FJ, simple...

I could not find anything similar, and that might be because people are shy to ask or do not want to ask, because as I mentioned "Showcase" in my mind as probably in other people minds suggests a finished product.

From dictionary:
showcase:
exhibit; display.
"the albums showcase his production skills"


What I am talking about is not "showing" skills, but actually asking for improvement suggestions.

In similar manner there are art shows and art workshops. Which are very different in their nature. In one, people display their art in other people learn.