-
That looks like it fits pretty well actually. The only bit I'd be worried about is the pressure from the lower half onto the tube, it's focussed on two points, although you have already protected it
You could probably fill the missing section of the bottom half of the clamp with something to spread the load if you wanted absolute certainty
The kickback 1 doesn't clamp to that bit, but when the stand is engaged the legs have a piece that meets the oval tube. But on the kickback 1 that piece is ovalised so meets it nicely (actually I think there was also a round tube option too)
Is that a 2018 frame ? I've got the green one (2017) .
Xtracycle suggest that they can't guarantee a fit because of the following - 'Boom tube slightly more oval than strap/band. Perpendicular tube fits KB3 plate perfectly.'