I would tend more toward the Manfrotto (and other) Superclamp – they come in a couple of sizes, and they lock onto just about anything: doors, poles, small children. They will hold quite a bit of weight securely.
https://www.bhphotovideo.com/c/search?Ntt=superclamp&N=0&InitialSearch=yes
They are made to take standard lighting fixtures in the socket, but there are all kinds of adapters (they often call them “spigots”) that make it able to hold 1/4-20 mounts – it actually has a 1/4-20 female thread on the front. Here’s a particularly ingenious one I just ordered from Hong Kong (I have yet to see them in the states) that gives you a whole bunch of mounting options:
https://www.ebay.com/itm/190657896758?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
Joe Bourke
Owner/Creative Director
Bourke Media
http://www.bourkemedia.com