Flashforge AD5M spool holder rear

Playing with switching colors, the machine can use an extra spool holder. I found a threaded hole that was positioned fairly well...
Normally I'd just drill holes and use threaded inserts but I only had this thing a couple weeks and trying not to do anything to void the warranty. The one M4 x 10 or 12mm screw is plenty strong enough.
PETG, 0.3mm layers took about an hour.