Hi Lewis,
Number One - A big thankyou to you for bringing this up, it took me a while to sift through the various explanations and versions, the pictures certainly helped, but I thought I'd give it a bash, and I'm glad I did.
I use Unger ErgoTec handles and channels (the handle holds the rubber in place in the channel) and normally have about 1/8th inch of Pulex soft rubber proud of each channel end. 15ml per gallon of GG3 with just a TINY squirt of Fairy so we can see where we're going, or we've been, on shopfronts. This usually produces a close finish to the frames and very little detailing is required, and mostly I just use the applicator and small blade to wipe the sill or Contico blue microfibre cloth for a one-pass wipe, but Unger large green microfibre cloth for detailing or "scrim" work - I know, each to his own.
Plan B
Nothing else has changed, but the channels are now dog-eared and the rubber is now trimmed to show about half of what we used to.
Result?
Mmmwah, Mmmwah, excellence itself - I was like a kid with a new toy, kept looking back to see if ANYTHING was going to show on the upright edges - not a thing. So far, I don't find I'm going through rubber blade any faster either.
Verdict?
Lewis, you am de MAN !!
Any ideas how it started? We reckon that some lazy window cleaner dropped his squeegee from a height, didn't look at it, or couldn't be bothered to fix the channel, and then wondered how he was getting a better job on one side of the window.
All the best, and thanks again.