Blu-ray aspect ratio change?

[Weirdo]

Hello, is there a way to change the aspect ratio of a blu-ray title/playlist within a BDMV folder (a complete blu-ray with menus etc.), without having to re-encode? Perhaps something like PgcEdit does in-place with DVD's?

Gave BDedit a try but couldn't find something similar (and it was a bit overwhelming, admittedly).

Would changing the aspect ratio flag of the single m2ts file(s) and just replacing the originals work, or would that mess up the BD structure/menus?

Thanks