I think two slots for a personal trainer job at The Edge would be neat. I believe it has the infrastructure, just needs a terminal. Someone could just do this on their own time but making it an official job and identity would incentivize both the RP and having midbies translate combat mechanics for lowbies. Would also be a nice half step for a few career paths and give bruisers a place to bruise in the downtime.
Can imagine weekly pay would look similar to other positions where one makes a wage but also charges clients. Job duties would include gathering clients, maintaining SparTek gear, facilitating spars, and just making the gym feel lively with fitting RP. More Mix jobs are always nice in my book.