would the apex breakout box also be able to switch the solenoids on/off?
No the breakout box cannot drive control of anything. It is just a continuity checker.
what does the 550 flow restrictor ensure before the water enters the kalk reactor?
The flow restrictor ensures 2 things. First is most solenoids need a tiny bit of pressure to open and along with the top-off pump this is accomplished. Second is when the valve is open, that path only has a tiny amount of restriction compared to the restrictor path and so the majority of the water will take the solenoid path.
All floats are now connected to breakout box. I did add another 'oh crap my filter pad and sock are clogged' float. I will probably be able to hear the change in sound of water overflowing differently into the sump but this is a nice backup just in case.
I added a digital temperature fan controller that I will use to circulate fresh air from the cabinet doors and also aim at the sump surface to cool it down a bit when needed.
I decided that I will eventually mount the ozone air pump and dryer to the wall above the counter top so as to start with less humid air and make changing the desiccant easy. I will eventually migrate one of the EB8s from my other tank and mount on the wall too for connecting up the lights and wave makers.
I got my lab grade PH and ORP probes. I am debating whether to get a salinity probe and use that in the mixing tank.
I got a cheap Full HD Chinese 9" tablet that I will mount to the upper cabinet and use as a monitor and controller.
And finally I added a temporary return pipe to the drain so I can perform a full water test and check everything out and fix any drips while it is still open and easy to do.
One thing I did realize I was missing was a RODI line for filling my dosing mixture containers and whatnot.
