Some RDBMSs have CREATE ALIAS, which allows you to refer to a table by a different name (while also referring to it by the original name).
We have an application running on DB2/UDB which (for reasons wholly unknown to me, and probably also to the current developer) extensively uses this with two schemas: MTUSER and MTQRY. For example, sometimes refer to MTUSER.sometable and other times refer to it as MYQRY.sometable.
My goal is to present a way to migrate from UDB to PG with as few application changes as possible. Thus, the need to mimic aliases.
Maybe updatable views?
CREATE VIEW mtqry.sometable AS SELECT * FROM mtuser.sometable;
I think views will work. Alternative might be interpose a proxy to rewrite the SQL. https://www.galliumdata.com/ gives you an idea of what this might look like although could do a lite version yourself.