What is you RNGFND_MIN_CM value? In theory, any range finder value, which is less that that or larger than RNGFND_MAX_CM should cause switch from range finder to baro, so if your MIN_CM is any bigger than 0 this should be already “filtered”.
@kuspower,
Thanks for the report. I’ve created an issue here. I think it is quite a simple fix but won’t make it into AC3.5 but could potentially go into a future point release.