Here is the issue to me. Say I download and install 10.5.12 and want to go back to 10.5. Sorry Charlie, cant do it unless you contact support or PM a moderator. If it is not in the Download Assistant or the version you need is not in the downloads section on the support area on Steinberg.net , you are screwed and have to contact support. REALLY REALLY STUPID.
ADVICE Save all your download installs somewhere so you have them if you need to get back to it. Otherwise its a major PITA.
Download Assistant is stupid as it does not connect up with your MySteinberg account which has all your registered products. Nor does it connect to the e licenser app that holds all your product licenses to see what you actually have bought, so convoluted. I LOVE how Presonus does StudioOne. Log into my account and select StudioOnePro, then which version I want , then the point version 4.6, 4.6.1, 4.6.2 etc, SO simple which is why I use it more now
Dont worry about Cubase complexity, just learn that ONE THING you need to learn to do what you need done.
NO ONE uses every function in this beast.
PM me anytime with any questions you have on Cubase, glad to help ya