Would you mind checking if the reboot issue occurs with specific fonts (or statistically more often on certain fonts) ? I recall I fixed this issue when migrating from CF8 to 9 and it was related to DMA and very specific timing issues (hence appearing only with certain fonts, problem being linked with the duration of the power off sound.
for the color profile, it could be the resolution of the transition when you move to a profile to another one which is very similar (on one die), like a variant of shade, but I don't remember facing this.
Feel free to email me your SD card contents so that I look at the color profiles, configuration and fonts. thanks !