... I've seen a "scanning XY-mirror" for a CO2-laser with 100kW power, which was 500x500mm ... so your'S is not "too big"
Viktor
Aufruf zum Projekt "Müll-freie Meere" - https://reprap.org/forum/list.php?426
Call for the project "garbage-free seas" - https://reprap.org/forum/list.php?425
I'll clarify - the size of the mirror with reference to the mirror! It is not typical for the mirror to be larger than the galvo.
Sincerely,
Ryan Smith
ScannerMAX Mechanical Engineer
ryan {at} scannermax.com