External Pressure Sensor integration with cockpit troubleshoot

We are developing a custom underwater autonomous vehicle, and are trying to integrate a va500 valeport altimeter with pressure sensor. This component uses a RS232 serial connection to output a NMEA string of the depth (from ultrasonic range finder) and depth (from barometer). I’ve made a python script to parse and send these readings as mavlink messages reverse-engineering an existing dvl extension’s methodology using mavlink2resthelper. Using SCALED_PRESSURE2 and DISTANCE_SENSOR messages, blueos is receiving these messages, as indicated by their status in the zenoh inspector. However when trying to integrate these messages into cockpit with the intention of using them for autopilot, cockpit cannot see or read these messages. How can i integrate these messages into cockpit for use with auopilot? Also is there a better way to parse the sensor data? Thank you