28~30...ok, the Fuji calls for 20* I believe?
Do any of the aftermarket systems ever have any problems? I know, any mechanical thing will develop a problem trust me I know, (I'm a full scale A&P mechanic at a major airline in Atlanta...hmm wonder which one... LOL)

What do you think of the Faraday cage idea? It shouldn't add but just an ounce or two, and if it provides a good solution )as opposed to shielding wires, moving things around, etc. maybe that's an option?