This has been asked before but now it's an issue for me because of a new work laptop that doesn't even allow me to use a USB drive... can the new universal installer with 12.20 install Opus without admin rights?
The old and new installers are the same in this regard, although we are thinking about non-admin installs (and being able to update USB sticks) from the installer as a longer-term goal.
(Not sure when. it's just an idea at the moment, and would have to function like a USB install, i.e. limited Explorer Replacement support, since installing some of the involved components requires admin.)
I'd love to get it without the Admin requirement. As a consultant, I get issued quite a few laptops each year for the customers I work with and I'm increasingly finding more of them locked down. Both of the ones I'm currently on don't even support USB devices so the dongle isn't an option. The next issue is how to download it because IT departments like this also heavily restrict the sites you go to... but that's not your problem.
I think at that point you're probably breaking corporate policy by installing anything, even if you can find a way to work around all the methods they've added to try and stop you. 
Depends on your point of view. The key word is 'install' and if it's a portable app, nothing is being installed. But yeah, I have to show some discretion and be careful.