I found the tweek on another site, I can’t see the point in more expensive top guides.
The B screw’s been the answer to some frustrating drivetrain conundrums for me in the past but it’s such a quick and easy thing to adjust. It’s not quite as sensitive as a gear cable adjuster, but still stick to no more than a half turn at a time. Whack ‘er in the big cog, adjust, shift up and down and repeat until it looks/feels right. The top jockey should be clear of the cassette as you probably know, you’ll hear it purr and tick if it isn’t.
The world’s meant to end today, there’s nothing to lose 😉