Harlequin,
for jerky throttle my solution was X-TRE installation with 5th gear fuel map, at the beginning of 2015. It solved 90% of the problem. Later on, all the story about new ECU came up and I went to my dealer who swapped the ECU, no questions asked. My original ECU had part number ending with "0" and the new one has the part number ending with "2". My dealer told me at that point that my X-TRE is not needed anymore but I kept it anyway on the bike. However, after new ECU, 100% of jerky throttle problem was solved.
The best way for you is first to confirm the part number on your ECU and if it ends with "0" or "1", start to fight for new ECU.
Also, read the long thread about new ECU.