I got the shock with the piggyback reservoir from OTR ordered to my weight including gear. The shock is S46PR1C1 YA817 with spring 01099-24/80 L3314 fitted.

I did wonder if the Ohlins settings were a bit on the stiff side because as you said working to the 1/3rd rule of thumb the the rider sag should be in the region of 67mm and not 40 - 50mm. I think i'll aim to set the whole preload front and rear to the rider weight of 1/3rd of the travel and see how it feels from there, it's going to feel a million times better than the tired stock springs and shock anyway.