@feyd
shader sets
Shaders can cause problems (I am not saying that they will cause problems, I am saying that there are some cases where they cause problems), it is recommended to test without a shader to ensure that this is not the case. Overlays can also create problems when configured incorrectly or at a higher than ideal resolution.
nes3pi
I don't know this case, but, for example, retroflag's cases have a script for safe shutdown (which also turns off the fan), maybe this nes3pi case has some similar option, but I can't guarantee it.
scart to hdmi converter
Perhaps this will interest you:
https://recalbox.gitbook.io/documentation/tutorials/video/crt/connecting-your-recalbox-to-a-crt-with-hdmi-and-scart
