My ol’ Big Top has a Thomson layback post. And it never stays put – doesn’t twist at all, but gradually lowers over a ride. Replaced the Yeti clamp with a Salsa clamp (QR), made no difference. Now tried the bolt up Kenesis clamp that came with my Tripster, done up tight as I dare.. put some electrical tape round to mark where the post was, by the end of a short ride round QECP the tape was mangled down inside the seat tube, so about a 20mm drop there. Had some carbon paste in there too. I’ve got a Thomson clamp looking pretty on the Tripster.. worth trying?
or is there a layback post worth splashing out on that’ll be a better fit than the Thomson?