The S912 devices were never a good choice, due to Amlogic only having licensed the android version of the Mali graphics drivers needed for them. So OS like CoreELEC had to use a Hack to work around this.
Unfortunately this Hack no longer works with the newer kernel that CoreELEC now uses. So support was dropped when the 9.2.x builds went EOL. There just was no interest from other developers or vendors that made/make S912 devices to help recreate the Hack for the newer kernel.