Ok, so we want to convert a .babylon file to glb, load into blender, modify the file, and reload into your scene?
That might not be a maintainable workflow without some flexibility on the part of the artist since you’re putting yourself at the mercy of two engines, two file formats, three importers and two exporters. If you’re loading a .babylon file into a babylon scene for usage, that’s fine, that should work as you expect but as soon as you want to bring that file into a DCC tool for further edits, its not necessarily a realistic expectation that everything in your new format, or even the same scene round tripped through glTF via babylon or blender to be identical to the input format.
Your only real guarantee here is that everything should look identical, but the data may not necessarily be preserved once your application consumes it, ESPECIALLY when you take in data of a given format and convert it to another format. You are now bound to the rules of your new format. As I would expect a blender file I give to someone else to use in blender to be preserved, I can’t expect a glTF that I create from a blender scene to be a 100% one-to-one representation of the original scene, it should just be expected to perform identically when loaded into another engine that supports the format.
Your expectations might need to be adjusted from “everything is identical” to “everything should load and look identical”. I would expect that my scene as it appears in Babylon and exported to .glb should look identical in Blender, or re-imported into Babylon from the .glb. Material namings may change, and object hierarchy may change, but the scene should still be functionally equivalent outside of coordinate system shenanigans.
To answer your other question regarding UV coordinate systems, I believe that glTF uses a top down texture coordinate system, while babylon uses a bottom-up, so UVs may not be 1-1 preserved as well.
Are you scripting anything in blender that is dependent on your object locations? Why does the local space transform changes break your workflow even though the world space is correct?
Also, is this a one time conversion you need to make or are you hoping to use a whole library of babylon objects that need to be roundtripped through babylon and blender?