SFX are assets and should be made during the game jam. Take a look around on the "looking for team" thread! There are loads and loads of composers and sound artists looking for teams this year.
I'm pretty sure the idea is for all the assets in a game to be made within the timeframe of the game jam, as opposed to pre-made assets we might have lying around. I'm assuming that as long as the sounds or what have you are made during the jam, the tool doesn't really matter.
