Independent Land Rover Specialist near Clevedon

[Sortie 10]

I have a 2016 Discovery Sport on 98000 miles that has thrown an yellow engine management light. The car is usually serviced by a non-marque specialist who has told me that it is potentially a £600 sensor but there could be other issues & suggested that I go to a main dealer - the thought of this horrifies me on service & cost grounds.
Can anyone recommend an independent Land Rover service specialist who is conversant with Ingenium engines
The fallback position is clearly using Sytner at Cribbs Causeway or Vertu Taunton - are there any clear feelings about which is the preferable (or least worst) option?
Thanks for any leads.