They make the claim "vaccines that pose 50% higher excess risk of myocarditis compared to an infection", and this is a misleading claim.
The risk to an individual of taking the vaccine is more sensibly measured against what happens to somebody who isn't vaccinated, not what happens to somebody who isn't vaccinated and also didn't die.
This is like comparing injuries in people who survive jumping out of a plane with and without a parachute. How important is it if people without a parachute break their arms less often?