Much appreciated @kersing, @cslorabox, @descartes, @LoRaTracker for your contributions to the discussion and improving my knowledge.
I think @cslorabox hit the nail on the head:
Also, location imprecision invariably implies time imprecision, since location in GPS is derived from time.
GPS was enabled on the RPi gateway purely for my academic interest and to learn a little more and see the impact on the metadata. I had noticed that other gateways were including their position information when one of my nodes reached out to them.
I wasn’t sure if TTN could make use of the more accurate timing data, but it sounds like it is not any particular advantage.
The MQTT data snapshot below shows the point before and after GPS enabled on the gateway.
It’s easy to see the extra decimal places on the “time” field, plus the insertion of latitude, longitude & altitude which was my original goal when incorporating the NEO-6M.
My altitude is bouncing up and down by maybe 10 metres from my reference height, but it can’t really be relied upon anyway because the GPS antenna is currently closer to the RPi than to the LoRa antenna!
Thank you all.