What happens to the authorship of your blueprints when you change Steam name? Do they transfer to new name, or does it show old one for Creator? Would there be any conflicts with some posted to workshop already? Looked around for a while, but didnt see results for this.
If you do not change your Account-Login Name on STEAM but only change your Alias there should be no problem with your BP's. Example: Log into Steam with Roosevelt, NAME your account Churchill. RE-NAME it to Patton. Your Login Name stays the same, all Game related info stays the same.
The blueprint stores the steam ID and the current avatar name, if the avatar name is changed, an existing blueprint avatar will not be changed. New created blueprints will get the new avatar name. Well you can also change old Blueprints names but is a completely different procedure and has nothing to do with the current Steam name.
Long ago I created a .bat file to copy save game information I wanted to keep into a Google Drive folder, EGS being no exception. I used the Task Scheduler to run this .bat file daily, so when it comes time to reload my work, or when upgrading my PC, I have everything I ever made at my fingertips, since copying my saved information is readily available.