I ask this because when that tank is inverted the bubble of air under the lid must pass through that center hole in the cage top plate in order to rise. It then rises through the center of the tank, nearest to the center of those spirals holding the sheets. I have had problems with overdeveloped edges because of this internal cage geometry.
And turning the tank back upright then causes the air bubble to rise back to the top of the tank. Often not all of the air passes back up through that center top plate hole. Some of it remains trapped beneath the top plate, causing uneven bubble-driven underdevelopment along the film top edges.
Because there are no plates in a standard roll film spiral tank, these problems do not occur.
Also, I do use blank sheets of film in all empty spiral slots to assure even and repeatable solution flow during agitation. Additionally, I have also experimented with Edwal LFN to reduced developer solution bubbling for the second problem, with only partial success.
Any possible agitation tips for another Nikor 4x5 tank owner?