It would save bandwidth by only downloading what's needed rather than all. For the most part, what works in T:ANE also works in TRS19. This can be done by creating a pull-down menu with branches if applicable for the different versions.
It means some extra coding, and in some cases extra storage space to ensure that both versions are hosted.
I thought of that too, but I was posting this idea as a quick low effort fix since the way Scratchy put his post, JR hasn't done much to distribute the new version.