I can only confirm 2 s-7's as I never had three on hand to test.

here are my two  one batch 1 with untouched firmware running both the batch 1 and  batch 2.

It got hot in NJ it will be 70f today so my two are downclocked to manage heat

At 50f I can run my two at freq 581 and get around 9300
at 45f I can run my two at freq 587 and get around 9400

at 70f I run at freq 562 and get 9080

some math  562/600 = 93.666667%   x 4860 = 4552  x 2 =  9104   and I am doing 9080  due to 0.0052% errors so no complaints