Mentioned here all the way back in 2019:
If I choose a specific transport type in the Extension (for instance picking TCP instead of auto) that setting should be reflected in the config generated by EPM.
Yes, you can alter the basefile, but then you are altering the settings for ALL the phones of that type and template - that’s not very flexible.
Scenario is a subset of phones behind a CRAPPY connection that become unavailable with UDP but work perfectly with TCP - but because I have to alter the basefile, all the phones are now running TCP even though some of them were fine with UDP.
Feature request I guess.