Sonar / Rangefinder when proximity enabled

When proximity for a forward-facing sonar is off, i get rangefinder and sonar range readings.
however when prx1 type is set to 4, i still get sonar range but do not get rangefinder.

i came across this because i was using rangefinder dist in a lua script that stopped working when i turned on proximity.

(rover 4.4.0-dev , matek H743 slim, hc-sr04 sonar)

is this expected behavior?