The fact that you're still undecided about which to adjust shows that you clearly haven't grasped key knowledge on the subject. Please reread my earlier post (#3) as often as necessary until you truly UNDERSTAND the functional difference between the barrel (trim) adjuster and the limit screws (both high and low).
Until you actually know what you're doing, you're equally likely to make things worse rather than better.
Sorry to sound harsh, but I'm trying to move you from someone who fiddles blindly, to one who can make adjustments to a purpose.
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All the above not withstanding, you may not actually need or be able to adjust anything to solve the grinding in high. Follow the link to an explanation of
chordal action, which causes derailleur bikes to feel like grinding on small sprockets.
In case the link fails because of a bias to HTTP
S, you can copy and paste this into your browser ------
chain-guide chordal action ------ and scroll to the "Chain Guide" site, disregard the unsecure site warning if you get one, and go to the http version. It's an old site, no longer maintained, but is safe to view in HTTP.
It's a PIA method but BF tries hard to keep us safe.