I think I have discovered the answer folks, and it's simple.
I could never understand people on the NC 750 forum having difficulty raising that bike which is a bit lighter and certainly smaller. But when I switched to the Africa Twin I was straining so much I pulled a muscle in my back Others on here were doing it with apparently little effort.
Then one day it popped on just like the NC750 used to and I realised that I had been trying to do it previously with the handlebars turned. If I straighten them up before pulling up it's almost as easy as the NC750 was. (I think the larger bike had been making me nervous about dropping it away from me so it seemed safer to turn the handlebars so the left grip was nearer to me - but of course the bike was in a 3 point locked position - two stand feet and the contact point of the tyre).
I don't think I have seen this mentioned (getting the front wheel straight) on either forum - probably because it's so obvious - doh.
And yes I use the left side pannier prong to lift with. It's just at the right height for me and I'd rather take the pannier off to put it on the centre stand if I have to.