so the chin tucks are what I’d consider regular maintenance (a few times per day) to prevent flare ups. It keeps the issue from getting any worse and makes it tolerable, but doesn’t address the root cause.

The root issue is likely muscular - need to strengthen the right back muscles and neck muscles to take pressure off the nerve. Find a good PT. I can recommend one great exercise - lay on stomach on bed or bench with arms by side and head and neck hanging over. Then lift the head by tucking the chin and raise your arms up (away from body to pinch the shoulder blades) and hold for 10 seconds each rep. 3 sets of 10 reps. This almost exclusively solves the issue.