If you want to have a single cutoff switch but multiple places from which it can be activated, take a look at the Cartek GT cutoff switch. It's a solid-state switch that uses normally-closed, momentary-off switches to activate or reset. I put one on my Spec Boxster, and it's been great.
Pegasus Auto Racing sells them:
https://www.pegasusautoracing.com/productde...asp?RecID=24996Or, if you don't mind ordering from the UK, Demon-Tweaks has them cheaper, including shipping:
https://www.demon-tweeks.com/us/cartek-gt-s...tor-kit-242156/I ordered mine from Demon-Tweaks, and it took just over a week to arrive, but that was pre-pandemic.
You can also order extra switches from either site.
If you want the look of the old-style cutoff switches, you could modify them internally to act as a momentary-off switch to trigger the cutoff.
Also, the Cartek GT has a positive output lug that cuts off 1/10 sec before the main cutoff. I use it to drive a relay that turns off my ECU before everything else is shut off. You could use it to drive a relay to connect/disconnect the alternator output instead.