I watched all your crosspicking videos. Thank you very much for your hints. I have also watched many other videos of you. What I am missing - but maybe I didn’t notice that because I don’t speak English as my mother tongue - is how the muscles of the whole arm musculature are involved. For example the wrist stroke. You are addressing the ulnar here, for example. But what about the biceps. With the violin, for example, you can perform the vibrato with the muscles of the upper arm, forearm, (wrist) or finger, or a combination of these, each with a different weight. In this way, even the smallest finger movements, for example with the biceps, are controlled by the vibrato (“Going for the big muscle”). This is in addition to the joints and arm areas and quite helpful to know. Is this part of your PS-Primer? Very helpful I find your descriptions like “door knocking” or “waving”.
Pardon my English. I hope I have expressed myself halfway comprehensible.