Hardy Tropicals UK

climbing rattan palms, aerial branching palms, subterranean branching palms...

http://www.fao.org/docrep/x0451e/x0451e03.htm

how come I have never heard of these before?

are there no even half hardy versions in these new catagories

There are a few half hardy rattans - Plectocomia himalayana and Calamus caryotoides are two that come to mind. There will be others too if you can do some research.

For branching palms, some of the Hyphaene species will take a fair bit of cold.

Have to agree with you, Ken. I've felt the same every time I bought or grew a new one ........for the past thirty years