Here's the issue if you use it. For a VFR plane they kinda/sorta work most of the time. For a typical RV IFR panel you end up having to re-engineer it with a mishmash of extra stuff and here's why:
The "Radio" buss is good for only 12 Amps. Not enough if you have dual radio setup + txpr + audio panel, etc.. Heck, a Garmin 430w needs over 10 amps worth of protection on it's own.
To make matters worse, the two radio circuits are rated for only 5A each...not even enough for many modern radios on their own.
Then, the Ldg/Nav/Strb are all rated at 10A. Fine if you're using incandescents, but WAYYY oversized if you're using LED's.
The autopilot is rated for 5A, which is enough for some AP's, but not others.
Trim is rated at 10A, I rarely see many trim systems in RV's need more than 2A unless you plan on using AWG18 wire or something, but most of our trim uses AWG22 or AWG24. That wire will fry LONG before that CB blows.
Boost pump is rated for 10A which is fine for injected stuff that needs close to that, but most carb'd pumps only need 2 or 4A.
There is a circuit for "Gyros" rated at 3A, I assume you could use this for an EFIS (1), but not enough for 2 of them and you really need a separate circuit for each one anyway. Since this thing was created by the canard guys, no circuit for flaps!
Now, you still need to consider any other goodies you have in the panel like maybe AOA, hobbs, CO det, various map lights, electronic ignition, 12VDC power points, engine monitors, stall warning, backup instruments, flaps, starter, so on and so forth. Once you start adding extra CB's and switches to complete what you need, you just as well should have started that way to begin with.
Next, your switches are: Radio, Accy & Power (then lights and the boost pump). Fine maybe in a VFR panel, but in a good IFR panel you absolutely want to control the AP, the heated pitot, perhaps some cabin lights, flaps, maybe a wig/wag, most likely an electric primer switch, etc.. Now, if you add a secondary battery or alternator everything goes out the window. How about an EBuss of some sort?
Anyway, nothing personal against them, just believe me when I say it's highly unlikely to be a good fit in an IFR installation without adding stuff to it, and in my opinion once you start adding and working around it you've completely defeated the purpose for it to begin with! I would agree the CDI stuff is probably better than the EXP stuff, but again that's relative.
Polyfuses/Thermal breakers and such were popular for a short time decades ago and have long since been abandoned in the certified aircraft world. 'Lectric Bob has a lot of info on this history! Here's the short of it...if you're in IMC and a fuse blows do you really want something to try and reset itself continually?
My 2 cents as usual!
Cheers,
Stein