I did for about 4 years. DPX licence isn't mandatory as they would hire with ATC or PPL license. It's basically flight planning for jet owners who are usually part 135 and such. It's good for new entrants in the industry that needs a start. I learned to use NAVBLUE, NAT OPS planning, EUROCONTROL experience, and other international flight planning. Pay was bad as I started with about 19 ish an hour but Houston SOL enabled that little pay then. Most of us left for something better because of low pay and the company resorted to hiring outside of the US for low wages. They've gone full remote now after Covid. For some that prefers remote jobs, this might be a preferred option.
I'm open for additional info!