There is no doubt lmic works. The trick is to find the proper version of lmic for the T-Beam.
There are a pair of local dudes using ttnmapper with T-Beams on 915 MHz here in Canada. They gave me their copy of lmic, or so they thought… It produced a compile time WARNING saying board (T-Beam) not supported. Its only a warning. The IDE compiles the program source. Running the code, it loops in an error state: board not supported.
The local dudes have lost code control. They understand they are using one version of lmic, the version they gave me. In fact their build is using a t-beam compatible version picked somewhere on their system during the build process. They are not using what they think they are using, the code they gave me. No code control.
Now the t-beam is an elegant board featuring an esp32 with WiFi, Bluetooth, a GPS, a sx1276 Lora transceiver, and li-polymer battery socket complete with associated charging circuitry. I like. I like it a lot.