Just an idea
This topic is eventually more about OEM models right?
I think you should check first if you can build one packages for more boxes.
Like you have trio4k, sf8008, ustym which are the "same manufacture" but on build/feed side it's mayor and time wasting as for all boxes an own MACHINE feed is made.
I think you should have an "OEM-Machine" feed which has linuxkernel, hbbtv, kodi, webkit, chromium. Then eventually in Machine feed you have just a couple of packages left which specify the box.
For boxes with one driver and don't do OEM machine names it's maybe possible to add in the end of the build an extra file/ feed which informs the brand.
I do not know of bitbake this all is possible but I prefer fewer packages builds first and see then how to brand it better.