Through remote instruction, it can be easier to click a link than to scan a QR code to attend, at times. I understand there's a screen sharing system to scan QR codes, however this is still significantly more work than clicking a link, in my opinion. If the user is signed out then they can just be brought to the login page and redirected back to the link once they sign in, ideally.
If a professor doesn't want the link system in order to avoid others sending links to people who did not actually attend, they just wouldn't share the link in the first place.
Through remote instruction, it can be easier to click a link than to scan a QR code to attend, at times. I understand there's a screen sharing system to scan QR codes, however this is still significantly more work than clicking a link, in my opinion. If the user is signed out then they can just be brought to the login page and redirected back to the link once they sign in, ideally.
If a professor doesn't want the link system in order to avoid others sending links to people who did not actually attend, they just wouldn't share the link in the first place.