Seems my Pico has a fault and has gone to Pico hospital, borrowed a friends and now have a clear picture of whats going on.

Blue trace is o/s/f wheel
Red trace is n/s/f wheel
Both earthed at battery
All images zoomed in.
Capture taken from ABS unit backprobed pins 5 & 9 whilst still plugged in


Running voltage observed with slight voltage increase just as Lee suggested, blue trace is dropping out for 20ms.

Hub replaced as one unit with confidence of a fix, old one had a considerable build up of rust between pickup ring and bearing.

Hope this post helps someone else