We use PGADMIN4 heavily in my place of work. We use it, so tech support can connect to different postgres instances of our customers. We made some modifications ( unfortunately we didnt make them in a configurable way, its all hard-coded )
1. Currently the encoding is hard-set to utf8, we changed it to latin9.
2. Have a type of user that cant register/delete servers/databases. They should see a predefined list that they cannot modify, additionally we modified pgadmin so these users cant drop/create databases/users, etc.
3. Add a comment to the top of all outgoing queries performed by pg admin so postgres logs what pgadmin user performed the action - this is super useful because this way we dont need to add postgres users to all the servers, the comment is something like -- PGADMIN : $USERNAME --
4. I feel like the connection reutlization thing is kinda flaky, We get a lot of "prerequisite error" stuff in the browser, we deal with it by refreshing the browser.
5. Add support for having some other caching server ( nginx ) in front of apache. We were able to get this to work with a bunch of rewrite/retry cfg in nginx, but it was tricky.
pgadmin4 is awesome - we love it! great work