Sometimes the best clamp is no clamp.
I've started column clamping without using a clamp, running a heavy-duty velcro strap (or 2) around a column which looks like the one Rocksuitcase posted a photo of above.
The velcro strap material is 1-3/4 wide, cut from a big roll similar to gaff-tape. It has hooks on one side, loops on the other, so can stick to itself at any length. I have two 5' or so lengths of it which roll up compactly in the bag without weight penalty and any worry of nicking anything in the bag. They now cohabitate in there all the time.
I use them to strap either my entire mini-stand to the column (going around both the column and stand, with the stand legs folded up), or just the mic-bar and threaded extension long enough to get a good secure strap around, which is considerably smaller than the Manfrotto stand, depending on the situation.
Excess strap length just gets wrapped around an extra time or two. I pass the mic cables through the last wrap as strain-relief and to keep the cables tight to the column. The velcro holds securely, is easily adjusted, doesn't mar the surface or damage anything, and the entire rig goes up really fast. That limits time standing on chairs fixing clamps and disrupting the goings on, keeping things smooth with venue owners and staff and remaining low-key and off-radar for the most part with the other patrons.
Also works for securing a stand to a fence, railing or whatever. In that case it secures things from wobbling or toppling, but is not rigidly "rotation locking" like a clamp unless both straps are used with a foot or two of spacing between them.