I tried using a vbox md with ui2+overlay. Failure, only ui1 will load.
The main reason I don't want to do it on my current setup is because it's 710, and my impression is if it is to go into 810 as part of the release, it needs to be setup/tested on an 810 install. I don't have an 810 install, nor do I have a spare machine to install it on. I don't want to reinstall my current "production" server with 810 until the final release, so unless someone corrects me and I can setup new skins in 710 that can be part of the 810 release I'm SOL.
The only other option I can think of is to make my dual-boot desktop a triple-boot and add a lmce 810 partition, but I don't have the disk space for that.