Just my opinion of-course. Since I have not used Metahuman extensively, I cannot say for sure what to expect insofar as an consumer-grade level product but again, generally, aside from using the parts provided to make levels, like sections of already textured/material-ed wall parts to build out a level, having to make those parts to begin with (like your metahuman apparently) is sus, to me.
Animation packs I’ve purchased in the past have a layout level, maniquin and animation blueprint provided, etc. Stuff is basically ready to go with minimal effort on my part. Asset-packs have similar and a sample-level, I wouldn’t expect to have to generate a sample material, unless I was going for my own logic, etc.
Having to make your model here sounds like, modeling in a way, something I would have expected to pay-for and get in the product.
Go look at the Paragon models from Epic. That is what I would expect in a character, except here, the additional specifics w/respect to metahuman.