Making it compatible with retail would require some annoying changes, plus I pretty much only play Classic, so the priority for that right now is quite low.

Not closing though - it's under my consideration and may do it sometime.

Would love to use this on retail.

Refactoring the addon currently, isolating all Classic-only compatible code to separate files. It will make it possible to add support for Retail later on, as the addon will just pick correct modules to use, which basically do the same job but in different ways, according to the game version.

So yeah, Retail support can be considered planned, but before it comes I'll first finish refactoring and bring new features to the Classic version.

So, I have published 1.2.0, which has some preparation in regards to retail support. It loads a Classic-specific file that controls the layout, only when running Classic.

So far, addon loads in retail without any errors, shows the settings page, and colors the buttons even, but at the moment still lacks the core functionality of modifying the layout. I'll post updates when I get stuff to work and arrange the layout in retail.

I had a lot of issues making an addon like this after they changed the action bar in 8.0. Had some suggestions here, but never managed to make something functional.