1995 K75. Bike ran fine then tried to start and dead. Some dashboard lights and running lights worked. Culprit was a blown 7.5 amp fuse to dash and other systems (top fuse of row). Starter won't receive power without this circuit. Fuse blew because of oxidized engine off (kill) switch. Thoroughly cleaned it (don't lose springs), lubed with Deoxit D5, replaced fuse and all good. I went through a lot of troubleshooting. If you experience similar situation, look to the fuse and off switch first. Ride well...

Please clarify the length of "crazy long. Does your Brick have ABS? Does the hose you're replacing have banjo fittings?

I have a non-ABS Brick. The stainless steel replacement hose from caliper to rear master cylinder is approximately 330mm in length. It's fittings are the same on both ends. The hose in the photos below is rubber but the ss replacement has the same fittings.

Rubber doesn't really “dry out” in the same way as a liquid. Aging can involve oxidation, ozone exposure, heat and UV, along with changes or loss of some additives in the compound. These processes can gradually reduce elasticity and cause hardening or cracking. A suitable protectant may help with surface condition, but it won't reverse deeper material degradation.

It’s about time for a new set of skins and most shops are telling me they are unable to properly mount and balance the rear tire due to the mono lever design.  What shops besides BMW can do this in the Portland Oregon area?

That's at least a positive start to find your issue.
The solid green wire feeds to the 'kill' switch.
What you have jumpered will bypass the kill switch, fuse, clutch switch.
Do you have a volt meter that you can measure at each of the wires in the harness connector. This way you can narrow down where the failure is at.  Or at least try your jumper from the start switch terminal to the other wires in the connector, say green/yellow(coming from the kill switch) or the green/white(coming from the clutch switch).