RH 8 WIP file format?

If I remember correctly, WIP 7 used V6 file format for a while and I was able to go back a forth between them without saving versions. Eventually 7 got it’s own file format and I reverted to 6 for my real work till v7 seemed able to work fully for my workflow. Is that the case with the current WIP 8? I’d be interested in giving it a try.

You would need to save as Rhino 7 format from the Rhino 8 WIP to use the 3dm in Rhino 7. There are several new features being saved into 3dm files in the Rhino 8 format that Rhino 7 does not know about.

Will my UI and alias customization work?

I’m not sure what you are asking. We do not save any UI or alias cusomizations in 3dm files.

These cusomizations should be independent between Rhino 7 and Rhino 8

Sorry. I switched focus of my question. Basically, will my customizations, toolbars, etc., work in V8 WIP? Or have there been big changes that would prevent that?

They should work, but you would need to import them into Rhino 8 from a Rhino 7 export of settings