The FRoctors on that thread didn’t seem to think myocarditis from covid was common or serious.
IMO, whether Covid causes myocarditis is not the issue - you cannot choose to catch covid. You can choose to take this shot.
The amount of heart attacks and heart issues happening in young health people is not normal by any stretch: https://freerepublic.com/focus/chat/3988541/posts?page=357#357