It doesn't matter how they look at the optical clock readings. Whatever method they use, they get a reading that says the lower optical clock goes slower than the upper optical clock. No observer sees the lower clock going faster. I don't need to account for photons travelling through a gravitational field. Not when I can show you Einstein saying "the speed of light is spatially variable” year after year. Read this:
https://en.wikipedia.org/wiki/Variable_speed_of_light#Einstein's_updated_proposals_(1905–1915)
I still don't understand your claim. Are you saying that a group of tiny scientists living inside the top clock would measure a different value for the speed of light than a second group of tiny scientists living in the bottom clock?