Switching from Intel Mac with OS on ext SSD to M2

Yes, it is possible (if I understood the question correctly). I have had a bootable clone (made with Carbon Copy Cloner) on an external drive. And then used Migration Assistant to copy that data to a new Mac via USB (I think also a data-only CCC clone on the external would act the same).

> copying over just my user account

I usually do the migration manually. I have a bootable CCC clone and just Finder-copy all my data files to the cleanly installed system. That needs some planning ahead and a routine where to keep and find important and not so important files. And to remember to copy some application data files from ~/Library/Application Support, ~/Library/Mail, application prefs from ~/Library/Preferences, application license numbers etc.

There is no need to go through that hassle but I like to know where things are stored and do a spring cleaning after major upgrades. Rest of the family use Migration assistant and it seems to do a good job.