It's a bit of a bastard getting to the controller under the electric motor so I will struggle to get motived to get in there again.Can you take a short video or a few pictures of that and add some schematics? I'm interested in doing the same.
But I looked at the wiring diagrams from an online manual (Russian) to find the wire colour for the driver switch. Also identified the Boot hatch switch wire by looking at it.
They enter the connector on the controller next to each other so it was a cut and connect job to make the two buttons do the same thing. The magnetic switch came from a coffee machine and was to sense low water by a floating magnet. It is in parallel with the other switches and they all simply connect that controller wire to ground when pressed