Hugues, I tried all sorts of key combinations, to try and find some hidden ones!
It might be the MacBook Bootcamp keyboard mappings though.
Anyway, it's progressing better now...if I get a silly alignment, I just delete the model rotate the model back (equivalent of moving the camera too) and rescan... seems to work and a lot easier manual aligning
Don't forget these are small parts, Ø50mm and 120mm high.

PS Another quirk, when you're doing a scan and it aligns the to the model, the "cyan/green" area has to rotated for you to check...you'd think the scan model window would update and show you this. I rotate it to check the alignment and when it scan s again, it's at the back of the model again.... changes needed here Alfred_t_s... I know what it doing, it's referencing the start of the scan, not the active part.