Final embarassing enlightenment today. It's the pedals!
After dis-assembling BB for a third time this weekend. Creak Creak. I climbed off to open a gate and .. creak. (But I wasn't moving...Whoa that's a first!).
Having done all these exercises countless times, pushed, pulled, jumped on the pedals, lubricated and bent everything in sight. I'd never heard it while stationary before. - This was surely a result! It turns out to be my Shimano M424 pedals.
This was funny because I'd already discounted the pedals, having ridden not clipped in, ridden with one leg, pulled and lubed them. These pedals have a black nylon platform surrounding a standard double sided SPD cleat. When I ride hard, my aged and flexible SPD's push slightly on the nylon platform, causing it's nylon bush where it locates on the SPD insert to creak against dry axle. Lubing the SPD cleat itself, or the SPD bearing was having no effect on this joint. While riding not clipped in, I guess I was pushing the nylon outer, so they still creaked.
Climbing off a bit wonky at the gate I was pushing hard on the nylon SPD pedal outer (which I don't normally do), nailed it.
A dab of bike lube right then in the CORRECT place fixed it instantly!
So I deeply apologise for any inference that this was caused by either Octalink or EBB!
Closed.. Silence is golden.