If the B-screw is too loose, would it significantly increase wear?
Sounds to me like your Rear Derailleur simply can't cope with a 34 tooth rear cog.  You could replace the cassette with a 32 or 30 tooth maximum, perhaps find a smaller upper jockey wheel, or simply don't use the 34 tooth gear without drastic need.

My folder has similar problems with on its largest cog because the top jockey wheel is interfering with the cassette.  The teeth in the jockey wheel (pulley) directly touch the cassette's teeth.  I simply put up with it, because both are wear items and will be replaced in due course.