I would expect GPS lat/lon and GMT to be included in the engine data for identification purposes. An aircraft has dozens of GPS’s, it is just a chip, and could use an internal antenna. The additional payload of lat/lon and GMT is 12 bytes of data. OTOH, I would expect the engine data to be routed elsewhere to an external antenna. (GPS is receiving, engine data means higher-power transmitting)
There’s no reason for engine maintenance data to include time or position; more likely it would include altitude, temperature, throttle position, airspeed, engine speeds and temperatures. Time is mostly irrelevant, but could be added when the data packet is received.