Exchange Projects between Cubase 10 LE and 10.5 LE ?

Hi,

Yes, it is possible. If you would use any feature in Cubase 10.5, which wasn’t part of Cubase 10, the feature would be just ignored in Cubase 10. There is (almost) always the backward compatibility taken in account.

You might be interested in the Free update to latest Cubase AI Cubase LE version for all registered users.