Trying to create a global listener for all databases

(Oracle 12.2.0.1.0 64-bit over Windows 2012)

I've been looking at OpenLDAP, OID, and AD to create a global repository for my connect strings, but due to the nature of our environment, some applications cannot use LDAP or OID or AD and connect "directly" to the database with a hostname/port/SID.

I have been tinkering with the idea of having one server that will host two listeners (one for Production with IP filtering, the other for NON-Prod without IP filtering), so that I can easily "redirect traffic" during outages, upgrades, etc.

So far I have been able to register a database onto a foreign/remote listener without issues, but I'm having difficulty getting that listener to hand off the connection to the database.