Just went out to the garage to plug the bike battery in, turned the bike on to see if anything was different. The clicking noise was back, so I pulled an injector out and turned the bike on... It's firing the injectors randomly without me even hitting the start button. Looks like the crank position, or hall sensors and/or wiring is the most likely culprit.
I'll update with results, but I'm flying to the east coast until after thanksgiving, so it will probably have to wait until I return.