Thanks for the comments and suggestions.
The reason for wanting an antenna with some “oomph” for the higher HF bands is two fold. Firstly there is a strong possibility that a future challenge will include 10m amongst other things although the MT have not actually finally agreed what will be and when but we have taken on board comments from those who commented. The second reason is the rather obvious fact that the Sun is waking up from her slumbers and early indications bode well for a more active maximum than last time.
Now the morbid bit… if you work on getting “three score years and ten” roaming the Earth and the Solar cycle averages 11years you get to see 6 maxima in your brief period here. Most people don’t start playing on HF till they are late teens etc. and that brings the number down to 4. The first 2 maxima when I was licenced I was less interested in HF and didn’t experience them and the last one was a serious blast at times. It also was a pretty rubbish maximum as well. So realistically I have 1 more maximum when I will hopefully be able to play SOTA on 10m etc. I very much hope there will be more than 1 but… See it’s being so cheerful that keeps me going! 
So I don’t want to waste the next maximum.
A delta loop and 1/4wave GP for 10m are my immediate designs to build. My 1/4wave GP for 12m weighs about 170g and adding an alternative radiating section or adding a link will only add 50g or so and gives me a twin band antenna that can stay in the bag now. I’m also considering seeing at how lightweight I can make a Christman phasing unit so I can drive 2x 1/4wave GP to give a steerable antenna. I’m not sure if the weight and trouble setting up 2 antennas will “weigh less” than a small PA instead and I want to compare this against a delta loop that is steerable by moving the guy ropes and letting it rotate about its mast.
Anyway things to make now and things to try when the lovely Nicola lets us out of lockdown.
Once more, thanks for the comments.