Update: I never got around to producing a video like I said I would so apologies for that. In the interim I seem to have solved the problem.
Out of impatience I did something that was rather naughty which was to change two variables at the same time: I dropped the temperature by 5 degrees and used the magic tumbler that was collecting dust (Weber Workshops variety).
This produced a much more even pour consistently over three shots.
Then, based on the lack of volume from pre-infusion and even though the grind size was a full 10 points coarser on the EG-1 than I grind for the Decent, I increased the grind size another 4 points on the EG-1 (thanks to @DavecUK for emphasising this) and the pour was more even again, over another three shots.
Thanks to EVERYONE who contributed suggestions. This was a team effort and I’m grateful for your every contribution.
I can now enjoy the shots from my Izzo again (I really love using the lever).
As a foot note, Santa is delivering a Streitman CT2 to my Queensland Australia address today, exactly seven days after it was shipped from the Netherlands. It will sit next to the Valexia and thus the gauntlet will be thrown down.
One more footnote: I ordered green beans from Melbourne the day before the Streitman shipped via DHL from the Netherlands and according to the tracking app the beans are still sitting in Melbourne 😆.
And I promise this is my last footnote: my condolences to all English cricket fans 😁