I wonder if you install a 2nd oil sending unit to drive a relay to cut starter power if the engine has oil pressure could work. It would need to be a beefy contactor triggered by a small relay.
The Foot button starter is a mechanical linkage instead of solenoid to engage the starter gears to the flywheel. A starter disable would keep the starter from energizing, but the gears would still mesh.
I used to lightly touch the foot button with my foot to hear the gears while driving, bored or tempting fate? The foot button linkage engages the gears first and then contacts the button on the starter to energize it. When the engine is running you'll hear the gears before continuing to press.
