Correct, the Tecnam P06T are being used for survey (grid style flights, "mowing the lawn") at altitudes below 5000MSL. Single Engine Service Ceiling in POH states 6000, but you'd be hard pressed to get that outside of a drift down.
Geomni's parent company is an insurance company, that's why they are investing heavily in better planes and training. They are very risk averse. PIC has ultimate authority on whether a mission will fly or not. They will not question safety.
Each hub has different airplanes for different missions / sensors. I flew a P68C and the Tecnam. They are acquiring lots of 206's with G1000 suites. All survey flights are 2 man operations (pilot and sensor operator). They are beginning to have pilots be cross-trained to be a sensor operator as well.
I never had issues with maintenance. If I had an issue, I brought it up to the chief pilot and head mechanic and it was addressed promptly, whether it was while out on a mission out of state or local.