You could also try putting one or two dryer sheets in your under-seat tray, if you want a preventive measure there. I’ve heard that mice don’t like the smell of those.

Are you the original owner of the bike? When was the last time you had the tank off? In your photo, just south of the sparkplug wire, there is a blue spot. That looks like a rub mark, and not from a critter. Any chance something is rubbing on your wires, resulting in that condition?

The DIY silicone fix is a good idea. There is actually silicone hose at AutoZone that looks like heater hose which you could slit and slide over as a guard. I did the silicone repair once to a VW Golf that I owned. It ran great except when it rained, at which time it would simply die. One night (do it in the dark because it helps to see the sparks) with no rain, I ran the engine and then took a spray bottle of water to it. You only need a slight mist. My coil covering looked like it had been shattered based on all of the wayward electrical sparking, yet you couldn't see anything in the daylight. A slathering coat of silicone helped, but I eventually replaced the coil.

While you are waiting for the part to come in you can cover the exposed wire with a thick layer of silicone adhesive for insulation. also cover the exposed wires in the wire harness.

Cheers

RLBranson