If the kites you are talking about are depower kites then you can't exactly swap. Fixed bridle kites need a fixed bridle specific bar.
If you trim the angle on your other kites they are depower and the bar is not a simple cross.
You know you can simply put a rope " strop " from the top to top of each handle and hook in that way ? I have used bars on many fixed bridle kites and
have moved back to handles for the extra control available.
Kites: 2.5m Profoil , Quadrifoil XL kitesurfer, NPW 5 Danger.
Flexifoil: 1.7m Sting, 4.9m Blade 3, 9m Blade 2.
Flysurfer : 19m Speed 2 SA, 7m Pulse
Peter Lynn :18m Phantom, 15m Synergy, 10m Synergy, 1200 Farc, 460 Sarc, 130 Tarc, 5m Peel, 4.2m , 6.4, 8.5 C-Quads, 3.5 LS2 single skin.
Rides: Flexi / P.L. Frankin'Buggy , Shaped + straight skiis, sand skis, Coyote blades. Core 95 ATB. RKB R2 ATB .
Ken (K2)