I also had the start on the stick with an enable/disable right next to the mag/EI switches. I never had any issues with it. I understand the pros and cons of it.
I probably would consider it again. It worked well for me for a long time.
In the first iteration I had a big idiot (start enabled) light on the panel above the EFIS. Was impossible to miss.
When I upgraded to G3XT I wired it to a discrete in the CAS as a red alert. Also impossible to miss.
I toyed with making it more idiot proof. Like some kind of relay that disabled the circuit once the alternator was online for example. But figured it would prob add more complexity than necessary.

One other observation. I had my headset jacks outboard near the vents as well. I always thought that was a PITA. Whenever you?re getting in or out, I found myself hanging the headset on the throttle or down in the footwell somewhere on a hook. Perhaps give some thought to where you will store the headset for short turnarounds.

Richard.

Yeah...how about "it's not needed"? Adding unnecessary components to a system simply increases the complexity and likelihood of failure. Yes, we have only one engine, because there's no way to put a second one on the plane. But various engine components have backups (mags, fuel pumps).

Modern avionics have no need for an avionics master. Adding one is simply an unnecessary complication. All components can fail, including switches, and if you're switching a relay, now you have a second component that can fail.

I say skip the antiquated avionics master and use the E-buss concept instead if you're worried about flying with no avionics due to some electrical problem.