3ds Max Unwrap UVW modifier/UV Editor

Long story short:
Current employer requires me to learn Max. No biggie there. Maxscript seems easy as I already know Python/MEL/PyMEL and some other stuff.
Problem is that I’m very dependant on the UV tools I’ve coded for Maya. The functionality of Max UV editor is… very weak to say the least.
So I’m already looking at stuff to create and I’ve also looked at a few other UV editors. One thing I have noticed is that every single one of the UV editor tools (TexTools, PolyTools3D, etc) use a separate window/toolbar docked to the native UV editor in Max, and I’m wondering why it’s like this.

Is it simply impossible to do a proper integration with the 3ds Max UV editor? Talk me through the tech details!