When you run into such shallow water then the line system will disengage fully as well and you'll have exactly the same issues with respect to steerage.
I sailed with the line and kick-up cleat system for several years when I still was a cat sailing instructor and it is not my personal opinion that I was better off then in any way. As soon as you picked up speed the rudders would float up anyway.
And the trick with bungees pulling the boards down can be had with both systems. However these are also a good way to rid your sterns of your boat in a surf.
Wouter
With your “on off only” system you can’t operate the boat in water shallower then max. draft of the rudder so unless you are leaving from a dock you are at a major disadvantage over an adjustable design.
I leave from the beach and at low tide it’s 2 feet deep for a good 500 meters
to a drop off. No BFD.
With your system you’ll need to walk all the way out there and back likely damaging the reef as you go.
On the return your rudders will disengage all right but you’ll be without the helm and that’s outright dangerous oxymoron in my opinion.
I'd like to see more pics of the solution.. Thanks