I'll chime in with my little bit of experience in the matter of plant inhibition barriers. 5 years ago I placed about 700 square feet of our old household carpeting in patches on the bottom of our pond, adding gravel and road base to hopefully provide spawning sites for our newly added BG.
The intent of the carpeting was to prevent the gravel from disappearing into the bottomless mud. The sunfish have been using some of the spots each year. No elodea has become established on top of the carpet. The elodea thrives on the plain mud bottom.