Gen plots will not fit on the older Noob and JF cases.
I do not know about the current crop of rep cases, but I had, 2 years ago, attempted to fit gen plots on a JF case for a member. I had to modify the plots to get them to fit the case in an acceptable way.
If you are after the "flexible end links" look and feel like the gen (much more swivel play), then it will make a lot more sense to modify the rep plots on the rep case. Visually I do not think that the gen and rep plots make any difference when mounted on the watch.
I will therefore like to ask your intention of wanting to mount gen plots on a rep case? I do own a few gen ROOs, and I have also performed related mods for members. If you want my input, maybe I can help.