Hey Alexander,
Looks like your latest patch addresses the original issue I posted!
So now I can create a placeholder with the USERSET modifier without a superuser, while non-USERSET placeholders still require superuser:
```sql
create role foo noinherit;
set role to foo;
alter role foo set prefix.bar to true user set;
ALTER ROLE
alter role foo set prefix.baz to true;
ERROR: permission denied to set parameter "prefix.baz"
set role to postgres;
alter role foo set prefix.baz to true;
ALTER ROLE
```
Also USERSET gucs are marked(`(u)`) on `pg_db_role_setting`:
```sql
select * from pg_db_role_setting ;
setdatabase | setrole | setconfig
-------------+---------+--------------------------------------
0 | 16384 | {prefix.bar(u)=true,prefix.baz=true}
```
Which I guess avoids the need for adding columns to `pg_catalog` and makes the "fix" simpler.
So from my side this all looks good!
Best regards,
Steve
