What I determined (based on what Site5 had done) was that the user.ini file needs to be in the root of an album set directory. Having it there caused all my albums in these album sets to work correctly. So having it a the root of your domain directory isn’t something that cascades down throughout your site.
In addition - for whatever reason - the Site5 support team also changed the name of the file from user.ini to php.ini. Seems like it doesn’t necessarily matter.
With all that said, I’m still trying to address the steps they seem to be indicating I need to take with the change in PHP version on their side. Still a little fuzzy there. They seemed to be alluding to the need to update ‘site scripts’ on my end. Just simply haven’t had time to address things since Thursday.