It's a moot point anyway for adjusting the collimation of the focuser - it's an old model that doesn't have the option. Ron at Moonlite has offered an upgrade path for it to the newer model that can be adjusted. I have to think about whether it's worth the postage costs involved to send to/from US if I go ahead.
Before I go ahead however, I'm going to go and recheck everything anyway. So I'll check the laser as well using something similar to your suggested test. I did do a test where it was attached to the collimated scope, without the focuser, and I rotated the laser within the compression ring attachment. It did not inscribe a circle, but reflected back on itself. I think this is a valid test, but doubts are creeping in.