Hi, I cleared flash then tried booting on SD but still no luck. I still notice that CPU usage seems higher, around 200-300% when playing either 1080p H264 or H265. It gets particularly high on uncompressed 1080p blurays, and the stuttering is more apparent. Not sure if there's a way I can show dropped frames instead of just cpu usage.
It hasn't crashed yet though, maybe the lower clocks helped, but I'll update on that more.
As for the legacy build I use knaerzche's LE 9.2 legacy release here. Specifically
LibreELEC-RK322x.arm-9.2-devel-20200427213119-b7186bc-rk3228a-mxq4kpro.img.gz version. This boots in SD card just fine. The latest armbian rk322x-box xfce build also boots just fine on SD, but I guess it's too laggy for desktop use.