Reauthoring Menu Navigation on a Backup

[doctorm]

I've got a BD with two movies on one disc The menus are basic and non-java.
I'm looking to back up only one of the two movies but with intact menus.

Normally when you load the disc you get the studio splash screen followed by a menu page asking if you want movie 1 or 2.
This is its own m2ts, 00006, called by playlist 00001.mpls. This sends you to a new menu just for the movie you pick.

The menu that matches the movie I want to back up is 00081.m2ts called by 00005.mpls.

Is it wrong/weird/inadvisable to just delete 00001.mpls (the one that calls the main selection menu) and replacing it with a COPY of 00005.mpls, the one that calls the menu page for the movie I'm keeping? (Ditto the CLIPINF & backup files.)

It seems like a solid idea that a quick test shows to work, but I don't want to run into compatibility or broken navigation issues down the line because I missed something.