You post is very interesting. I too have a VPI Scoutmaster with Dynavector 20xL feeding into a Musical Fidelity A308. It's a great phonostage for being inboard, don't you think?
I had the same problem, a light crackling echoing high soprano voice and some high staccato piano passages. I tapped in the counterweight about a millimeter, (my audio guy set my TT up and I don't kwow where he set the tracking force, I hope it's not too much now, I'm waiting for him to call back), and it removed the problem, except for a very few passages of which I have since tested on multiple pressings. Same problem, whether London/Decca/SXL.
One of the worst offenders was Solti's Strauss Der Rosenkavalier in the final Rose trio; luckily it's not a problem on the Karajan EMI. I find it interesting that the VPI tracks 99% of other, sometimes insanely demanding high vocal and/or piano passages without any problem at all, why is that? Some pressing simply may be incompatible with some turntable combos. Luckily for us, as you seem to like Classical, we get to choose from many performances and pressing of the same thing.