Make 'gid' column in 'node_access' table VARCHAR

Was trying to get both field_permissions and content_access modules to work, and discovered this node_access business for the first time. I've realised that most modules dealing with this have used Drupal's role rid as the gid when writing access rules, which is logical because it maps roles to grants simply, but the gid column is INT. Backdrop no longer has a rid, so to get his to work, I've had to write a doubtful function which maps each role to an INT, stored in config. Not fun.

Can that column be changed to simply accept the role's name rather than a rid? What would be the implications of this?