I’d considered taking the formula number three here as a basis. The height string in the NMEA message is referenced from the ARP and neither both phase offsets, nor the survey pole height are not included in it.
Also, there is one more point to consider: the NMEA message includes the geoid separation height, which comes straight after the number you’ve highlighted on your screenshot. You can consider summing it up to your measurements depending on your use-case.