That's a good idea. I was thinking of doing the same but putting both the stereo and the TV antenna booster on the same switch. The antenna booster off/on is the one I always forget. Though it's isn't really a big deal since I have a complete battery disconnect.
What I would really like to do is have a independent, hidden but easily accessible power cut-off switch for the power jack.
2014 Surveyor Cadet SC189
2013 Ford F150 XLT 4x4 Supercrew 3.5L "Ecoboost"