Better yet if you have aero brake levers set the bars and levers up so the tops and the levers are set up like you'd have with bullhorns. Try it out on a ride before you cut anything. When you've adjusted it to where you like it then hack the drops off just at the base of the aero lever mounts. File off any rough edges and bartape up what's left.

Being a practical person that realized I would not use the drops and that I could easily get as aero as my rotting old body could manage with bullhorn like positioning I did this to a recent build. I'm more than happy with it and it's only slightly less appealing than true bullhorns and TT levers.

If you use the clamp on cross levers on a flop and chop be sure you run with as little free play in the lever as practical. Most cross levers don't have a pivot point and the cable will bend and kink repeatedly at the ball end. This WILL lead to premature cable failure. If you use this style of lever then inspect the cable right by the ball end frequently and keep a couple of spares handy to swap out when you find a broken strand.

There was a thread some months back about someone that had one or both brake cables snap on him right at the ball end thanks to using these levers in a way that was never intended. On the other hand there's at least one brand that has a rolling anchor point which would work well.