Walking between sol/s, submits, and developer fee

In many posts I read the question: do sol/s include or exclude developer fee?

This question should be asked differently. Let me explain.

Each miner submits to the pool only a small portion of its solves.
The reason is that the pool can’t process all the solves from all the miners on time.

To reduce the load, the pool dynamicaly sets its target difficulty, which means that
only when the hash of the solve is bellow a specific number it is submited to the pool.

The pool knows the probability of a solve to be submitted and by counting the rate
of submited solves (shares) can estimate how many sol/s the miner produces.

This means that the pool knows only about submited solves.
Thus x% developer fee means that x% of the submited solves (called shares)
are credited to the devloper instead of the miner.

The rate of submitted shares is proportional to the speed of the miner and to the
target difficulty that is controled by the pool. The pool increases the difficulty
when the load from all miners increases and decreases it when the load drops.

Conclusion: the developer fee is tied to the rate of submited shares not to sol/s.