Since I last posted to this thread, I've developed two more rolls of 35mm film. I used inversion agitation for both, following Ilford's method of 4 inversions during the first 10 seconds of every minute. I did deviate a bit and performed gentle inversions continuously over the first 30 seconds of development. I also finger-squeegeed the film (the horror! ) after the final rinse since that seems to have eliminated the frustrating streaking I have been experiencing for months.
The first roll of film looked great - no streaking and no signs of the issue that I spoke about at the start of this thread that sort of looked like surge marks or bromide drag on a couple of frames.
On the plus side, it seems that the streaking I was experiencing before has been resolved by finger-squeegeeing the film.
I have been finger squeegeeing for years and largely I follow the Ilford method with the addition of the first 30 secs being continuous
I wonder, can we classify the above as the "British way is best?" No, on second thoughts just ignore that line. The best way is the one that works
Seriously I hope this is a permanent cure and not just another false dawn