Bad AHRS using new Omnibus F4 Pro HAL

I am trying to use Night-Ghost’s fork with the new HAL that supports this all in one board. Everything works well on the bench except for one thing. I get consistent bad AHRS if I use the EKF.
-I have recal’d ACCs many times
-Made sure the board is absolutely still during power up for gyro cal
-GPS has 15 sats and HDOP of 0.8

Questions:

  1. does the fact that this board have only one ACC affect this even though Pixhawk level code is being used?
  2. what is the impact of ignoring the warning and flying since everything on the ground seems 100% functional?
  3. Should I disable EKF and fly ? I am not looking for precision in navigation (like pre 3.4 days)
  4. Is there a param I can change to make it more tolerant? (If I change to EKF3 the warning goes away, but arming is still prevented with a “AHRS and GPS are different x meters” message…

thanks