Honestly, the easiest solution I can see for your panel is one of two things.

If you just want a second com, replace the audio panel with a PAR200B from PS Engineering.

OR

Install a Trig TY91 anywhere in your panel except the stack. You are overthinking this in my opinion. Just put the com where the Carb temp is, and put a carb temp probe on your EDM.

I also thought of the PAR200 option in response to the original question. https://www.ps-engineering.com/PAR200B.html I haven’t met anyone who is using one, but will be interested in PIREPs.

PA12_Pilot wrote:I also thought of the PAR200 option in response to the original question. https://www.ps-engineering.com/PAR200B.html I haven’t met anyone who is using one, but will be interested in PIREPs.

We put one in our Dakota a few months ago and it works great. Over the years I’ve been very pleased with every PS Engineering product I’ve used.

Thanks for the report.