Same last name and first initial as your handle so I took a guess. :)
> I was referring to the ability to assign a user to one or more groups and then set, at the group level, access to a row or column. When I implemented this, I avoided using PG roles b/c I was unsure how this play safely with future changes to the hosted DB.
This can be done with Postgres' built-in role system. You can assign a "group role" to as many roles as you want (which in turn, can also be groups, or not) into a hierarchy of roles which can be used in any GRANT statement or RLS policy. Postgres used to have `CREATE USER ...` and `CREATE GROUP ...` but they are now completely subsumed by the "new" role system. Both statements still work and map to equivalent `CREATE ROLE ...` statements.