Up until the pandemic (and I hope soon again) I have done a lot of world traveling, very light, with no checked baggage. Needless to say that makes photo equipment a problem, and I've long sought the most portable support possible to carry.
What I've taken on a number of occasions is a Promaster clamp. This comes in two sizes, of which I believe this is the larger. It is quite versatile, clamping to chair backs, railings, trees, etc., as well as serving as a table tripod. It's disadvantage is that the screws must be very very tight to keep from sagging. Right now it has an Arca Swiss clamp added, but I usually travel without pads on the camera and just screw it on.
Long ago when I actually did check a bag on a Hawaii honeymoon, I took the Linhof clamp. This has the advantage of size, and can be set up as a stable table tripod, as well as clamping, and has a screw whereby one an screw it into a tree or fencepost. The disadvantage is the large top, which is not readily adaptable to quick releases, and it's a little big for carry-on. I've seen others with smaller top pads. If you don't need to economize on space, this is well made and surprisingly stable. Used ones can be found here and there. The clamp is good and doesn't need to be overtightened.
Finally, not yet taken on a trip, is this little Braun clamp I just got for next to nothing. It is tiny, 35 grams, maximum 7 x 13 cm when flat. The ball head is tiny, and yet it clamps very securely, and allows table top stability easily. It also has a screw for attaching to a fence post or tree. This will likely go in the bag next time I travel.