A few other things to note.
So, as I went through this process using the plugin method I also found the following things that I needed to change.
- Behaviour for uris appending "?invalid=true" would trigger for both forms so I had to change them to "?invalidLogin=true" and "?invalidReg=true" respectively
- tabindexes were contradicting each other, so I changed the registration form to use tabindexes from 11 and up.
I'll post back here if I figure out any other elements that need to be changed. :)