This process of upgrading our system has me confused about how to handle our current commercial licenses. I need our production server to remain intact during the conversion and testing of the new FreePBX 14 server. If I remove the commercial licenses from the production server to test the new server then the production server commercial modules do not work. This is bad because it may take me several weeks to get set up and complete all testing of the new server. It seems like it forces me to buy new licenses that I already own. How do other people handle this?
You purchase them for the second PBX. Commercial modules are not designed to run concurrently.
Migrating FreePBX to FreePBX is, typically, a simple process. Why would it take you weeks to test?
If you have all kinds of customization, then by design, you can afford the limited additional cost more licensing would be.