Hi all! I thought this would be a simple issue, but after researching the web for over an hour it seems that it is not (or I'm dumb):

I have a custom object with a few different record types and I want a user to have read-access on all record types, but write-access on ONLY 1 of the record types.

Please don't say I have to control this through page layouts and edit every single field (that is absurd). I tried sharing settings and assigning them a different role, but that didn't work. Any thoughts? I wish I could just control record type access in a profile or permission set, but it seems they only allow me to restrict what record types a user can create, not view/edit.