Bummer, so I didn't find a solution / fix, but I did find some possibly helpful links.
These are options that I researched very deeply in any and every way possible. Notes for found possibilities are noted below the option, if any.
Opt-1 .) Locate where the files or code for the built-in SuperUser are located within ROM and update / replace them with newest version of SuperUser, and also gain root when re-root is needed.
Opt-2 .) Replace SuperUser found in CM-based ROM's Settings with newest version of SuperSU by either deleting from ROM's Settings somehow or keep it and have SuperSU built in ROM's Settings same as current SuperUser.
I do believe that somewhat of Option #2 might be possible. I don't really know for sure yet, but I found these other 2 links that look pretty interesting.
I know you can install SuperSU and pretty much ditch SuperUser for good, but then you still have it sitting in the ROMs settings for no reason at all.
You can remove and hide SuperUser from the ROMs settings but in order to do that you have to completely disable root. You can remove it by going to Developer Options or SuperUser settings and choosing "disable" for SuperUser Access. Unfortunately when doing this SuperSU immediately stops working even when open and closes the first chance it gets.
If anyone else can shed any light at all on the subject, it would be VERY MUCH appreciated! Thank you!