Wiring options for a single magneto ignition with 12v engine instruments

I have been thinking about how to set up a hand-propped, single magneto ignition with a ground-charged, battery-powered 12v circuit to power some engine instruments and maybe an anti-collision light. Altimeter, ASI, and compass would all be analog, no power required.

This type of three-wire, ON-ON toggle switch is used in racers and dune buggies to control the magneto and a low oil pressure warning light circuit (sometimes powered by a 9v battery) simultaneously. https://www.summitracing.com/parts/lng-45430

So one option would be to use two separate ON-OFF toggle switches, one upside-down to ground the magneto and one right side up to power up the 12v system. A second option would be to use the ON-ON switch with a 9v low oil pressure warning light or just a magneto hot warning light along with a second ON-OFF toggle for the 12v system. A third option would be to use the ON-ON switch above for the magneto and the 12v system, probably just the engine instruments and warning light since they are not needed with the engine off anyway.

Anyone see any big pros and cons to any of these three options? My initial thought is that I prefer option 2 but I am open to other arguments.

Cheers,

Matthew