Personally i appreciate that OS4 dev could drop an eye and play with Efika ! Even if Hyperion wouldn't license any motherboard (SAM, Efika, ..) for OS4.
In France (mostly Pegasos users for historic reasons), the Pegasos dev Corto (Pointrider, Wow, last Songplayer..) use too A1/AOS4 apparently : he's code for all Amiga "sects" : classic, MorphOS, AOS4, etc... I love this guy !