Firmware suggestion
Not sure if this is the right forum to put this in, but thought it was worth suggesting if (like me) you manage to loose a print several hours in after changing the filament and it gets stuck.. and you manage to move the print head when pulling it out manually.
No idea if this has been suggested before, but here goes anyway:
Basically after a filament change, I think the head should move up to the top of the Z Axis, in order to check it's position, then while there check it's X-position based on the extremes, and also for good measure test the Y position on the bed by moving that back & forth. It can then re-adjust the head & build plate back to the correct position for the next instruction so that it's not printed out of alignment. Moving to the top in order to do the X & Z calibration should avoid issues with the head hitting the printed part, unless of course the filament runs out at the top of a very large print (like the last 2 layers)
Also this should likely be an optional setting like the crash detection etc, and (personally) I'd prefer it to default to 'On'.
Granted this could also be avoided by not being dumb when changing filament, but it does seem like it could be an improvement were this added in.