Are you sure? My first thought is a gas stove (like mine) would run on 120 not 240V, as the only reason it needs power in the first place is to operate the low-voltage electronics and possibly the igniter which would consume something along the lines of milliamps. I suppose not all stoves are the same.
And then, how would your setup tell the difference between the stove left on versus you’re just cooking food?
Finally, what would your Insteon-based network do to inform you of the problem? Would you, or somebody else, dedicate a light or something to this? If it were me, I’d ask myself why not just buy the gas detector for RV’s and stick it on the wall so it can reliably just sound an alarm without the fuss of making it Insteon?