Janitrol heater and front engine fuel flow

[B2C2]

I have a Janitrol heater in my T337D that I have never used, but it is serviced at annual. It is usually quite comfortable on a sunny day up front and no heat is needed. however I did use it this last January on a flight to Santa Barbara from Livermore because I had a passenger and they weren't comfortable. On the flight down, I noticed that the front analog fuel flow gage was twitchy. wobbling by about +-0.1-0.2gph. I could detect some engine sound changes with it as well, so I think it was real. In subsequent flights without the heater the analog gage is rock solid, and no engine sound shifts, so it seems like it has something to do with the heater drawing fuel. From the service manual it looks like the fuel is drawn from the front engine fuel strainer, so its part of the fuel loop for the front engine and therefore a possibility. I spoke about this with my A&P and shared a video I took of the behavior. He said he hasn't seen anything like this before, and wasn't super concerned about it based on the magnitude of the wobble, but suggested I post here to see if others have seen this behavior and if so what is the cause or fix for it?. The heater started and ran as expected, producing plenty of heat. I should add that I usually run LOP, so front engine fuel flow is around 9.5 gph in cruise.