Let's offroad / mountain bike / mtb / ride dirt

I'm not denying your pain. I'm saying run the seat post at a height that is comfy and learn to ride 99% of the trail like that. Use a Q/R for the 1%. Forcing yourself to ride with the saddle up will allow you to ride more stuff quickly rather than fiddling with a saddle on every bit that is a little bit rough. You will probably only find yourself dropping the seat post if you are playing on some jumps or repeatedly doing a drop to work on technique, in which case stopping and using a Q/R is no bother and allows for a large amount of moment of saddle.

+1

If the saddle is hitting you in the chest on the descent then you might want to drop it, otherwise you can leave it where it is.