More parts, more modifications, more points of potential failure, more stuff to clean...
Part of my original design goal had been to replicate my hand process as accurately and directly as possible. As I invert the tank by passing it from hand to hand as I turn it over, but also give the tank a 1/3rd twist each time to reduce the risk of turbulent flow patterns showing up on my film.
However that leads me to a lot of problems. Either I need a design that can pull the whole lid off and put it back, or I need a new lid that has two ports in it [one for chemistry and another to let air in].
Beyond that I need some scheme to get chemistry from their storage containers into the development tank, but keeping the dev tank free to invert and rotate. Using pumps and tubes meant either having a system that connects and disconnects from the dev tank [headache point of failure?], or having the store tanks locked to the dev tank and just let them go along for the ride.
That lead me to the idea of just going very far along the 'mimic what I do by hand', and design it in part with a clamping cover, kind of like paint mixers clamp down on a can of paint. Then just pour chemistry in and out... But mock ups for that kind of design grew large, and dealing with smoothly pouring between containers without excessive splashing seemed like a bit of a headache.
Having a handful of containers set up in a tight pattern, and an arm that picks the reels up to dunk and move them from tank to tank as needed is sounding more and more like a simple and sensible working solution that needs far fewer parts and controls.