How to make the new FP-Character react to forces?

I am using the new First Person Character from the Beta Sample Assets. I have explosions in my scene, but the FPC-script overwrites the velocity with every physics update. So I can’t use ForceMode.Impulse on the FPC rigidbody. I tried different options from disabling the velocity overwrite when not grounded (which i thought would be working, but it sadly wasn’t) to changing the velocity directly (with jaggy effects).

Has someone an idea how to change the script (or create an entirely new one), so the character actually react to rigidbody.AddExplosiveForce() and disables or weakens the control while in mid-air through the explosion?

I added the script in question here, but i am open for better ideas:

There is no simple solution aside from simulating it with some kind of transform.position jazz. The FPS Controller just really hates physics i have tried many things but the best option is to just make your own character controller/ find someones character controller script online.