I installed rotating mounts, and what I've personally found is that I could get 5.1kWh from a 1kW array on a February 8th years back. With it stationary I would expect no more than 3.0kWh, so close to double.
In the real-world, here is a more important consideration. At 8:00AM, the sun is at such and acute angle to the panels that your 10kW array is only putting out ~1000W, or 10%. By rotating your panels strings eastwards, you can easily double or triple that.
That becomes very important to me on days when I want to run my well-pump. I find I can make the 2000W needed to run my pump at 8AM when facing eastward. If they were fixed and facing South, I'd have to wait till 10AM to make 2000W. So, rotating mounts give me at least 4 extra pumping hours per day. So, I can get 8 hours of pumping done with zero battery depletion.