does it make a difference that they are sti levers?
Aero road levers are rather high leverage,
little "work" (cable pulled) moved for a long swing of the effort arm
may bottom out before the brake does enough.
But , there is an Inline Travel Agent, [made for cable disc brakes]
just needs to be anchored somewhere , like to a braze on.
I'm using old cable out the top Campag brake levers on mine ..