done a little schematic.
I guess one obvious downside is that if the Supercharger isnt "warmed up" - your cabin heater might be a little lack lustre.
I've shot off an email to the KC guys.

Aside - cooling the fuel wouldnt b as effective - since due to the AFR mass ratio being 12-14....any cooling you do on fuel will only have an effective reduction of 1/12th that of cooling the air.
Having said that - due to contacting patterns an any Heat Exhanger - it might be possible to chill the fuel to 40F (consistently) than it is the air.

s