I have shortened it 10mm at the top and 5mm at the bottom. I didn't want to take any more off in case I struggle with the seat tube mitres and they end up a bit lower than planned - this was the trickiest bit on my first build. My mitreing should be better this time

What causes the seat tube to bulge Doug? My biggest tip is a No7 multi port tip, I was going to use this one for this job, just heat the sleeve and try and get the silver to the bottom with the minimum of heat and no direct heat on the ST.

Will go for it tomorrow if I get time.