Yeah, it seems like i was misled by the design, and too focused on the "buy" button and the lack of documentation on how to install the OS.
So they are using the generic arm builds from libretro "core updater" ? Well, considering how big the impact of optimized cflags is on those platforms (i think we are in the range of 20-30% performance gain here), they should give optimized packages and a tool to update them from sources like retropie and pretty much any of those retrogaming distros.
Not sure when or if that libretro generic arm buildbot will be back, its disappearance might be permanent tbh since those platforms usually make their own optimized builds.