Many thanks for all the advice guys,
I will certainly try the “tape” method this weekend to how that works out. As you’re looking at the base of the convertor, it’s the three pins on the left that you tape over, correct???
I think I would rather buy the 400 f5.6L to accompany my existing V1 100-400L, I believe the IQ with the 1.4 convertor will be better than on the zoom, plus it’s the same price to upgrade the zoom to the V2 as it will be to buy a new 400mm f5.6, so a no brainer!!!
Thanks again for all the input and images, you guys rock