... All builds that I made, I use it as a secondary rom and everything works without a problem with that cm12.1 base. If you'd like to use this rom, all I can advise you is to restore your main android rom, root it, install the multiroom TWRP, install kexec kernel and then you will be able to flash this cm12.1 and sfos4.0 as a secondary rom. I don't use sfos on my hammerhead anymore and as I've put /e/ os on it so cannot test whether I can install it as the main rom. (As the device doesn't have an external SD card, it would take lots of time and effort to back up what I have on it already. I might try that but don't promise that. )