This weekend I’m going to rebase the grayscale changes and publish a bug fix branch like you’re describing. The bed heater will be on that list as well. Currently those changes are built on top of Marlin and not on top of snapmaker firmware, with a few thousand commits in between.
My solution to this has been to move the toolhead to the position I want to change it, and then changing out the head/bed without unplugging the connected tool. Lights are on the whole time, and I can get the new head attached, and then just power off, change the plugs, and power back on.
It would be nice to have a setting for “enclosure lights always on” though.