Drac, yeah you can cook lots in them.
Jetboil themselves say that they are only good for water.
I think its just that its such intense heat in spots that unless your careful it’ll stick & burn.
I only use mine for wet ration pouches and hot water for a brew. Mainly first thing in the morning when they really excel.
That’s not to say you can’t, but it’ll be easier with a pan & stove.
The joy of stoves is that its n+1 on a much more affordable scale! ?