All sorted now, got it fitted ok.
Just a note though, in my efforts I discovered H9 and H11 bulbs are NOT actually quite the same fittings. They are like a mirror image of each other with a very slightly different locating tab in the middle. Like me though at first glance you'd be forgiven for thinking they are identical.
So I've had to fit the HID to the main beam after all, however it does come on almost instantly which is fine, even if it takes a few seconds to reach max brightness. I butchered a H9 bulb to make a block connector so everything is wired up nice and neat. The ballast block is zip tied to the small black bracket on the inside of the left fairing panel.
All I need now is to get out in the dark and see how much better it is.