The best thing I’ve done for overall health that really helps with joints, tendons and muscles is a carnivore diet. Keto is also good. My tennis elbow, and neck pain is gone. Try it for a month. Dr. Ken Berry on YouTube has very informative videos on it.
If you use a turntable vise, no matter how you tilt it it will stay centered. There’s no need for dowels or anything. Just rotate the table with the vise on it and observe the pivot point. Move your scope over it to where the pivot point is in the middle of the field of view. Takes two seconds.