@dc42 Thanks for pointing that bit out. I had missed that on the docs site. I filed it down some and it seems to be at a more acceptable range.
thanks for your reply @T3P3Tony
I will use that and see how I go. It makes sense to use the longer one. I did a print last night that had a fair bit of retraction and it only got down to a min 94% and a max of 107% over 9m of filament using the newer mm/rev.