I’ll confess that I have become completely addicted to T-bar leathers (like Webbers etc) which do not have a buckle at the top. The smoothness under your leg is a feeling you get very used to, and I now detest having a buckle under my leg, even a supposedly flat and comfortable one!
I wanted to use the same leathers for SJ and XC, but have heard of the T-bar part coming out of the slot when used for jumping. My solution is to wrap the join with duct tape so that it cannot inadvertently pop apart.
I know some people say that it’s not safe to use these, but when I bought my Butet saddle I asked Anki (who knows a lot more than I do about it!) and she said she couldn’t see any problem with using T-bar leathers for jumping.
This solution is quick, simple and easy.