I still can’t get my head around how cross top levers work on cantis and vees but that aside, does anyone know if they will work on normal side pull calipers?

Assuming you mean normal road brake calipers, then yes, they will.

Cross top levers effectively ‘push’ the cable outer when you pull the lever and that pulls the inner cable through it (since it’s fixed at the normal brake lever) just as when you pull the normal brake lever.

Marvelous, thank you.
I’ve fitted some before and sat watching whilst alternating between the drop lever and the cross top lever and been amazed at there being no movement at the brake.
It’s the little things.

Dime bar… 😉