Here's the deal, and I will end my discussion about athletes with this:
Evidence-based medicine requires us to explore all possibilities and entertain differing ideas in order to find "truth," effective treatment measures, and prevention strategies.
In this case, there is one side that says "because we now know that mRNA shots have been linked to myocarditis and vascular inflammation, it would be prudent to perform noninvasive screening exams on athletes and other people whose professions put them at increased risk for a major cardiac event." The other has accepted that adverse events from the shots are extremely rare and that we don't need to worry about long-term complications.
Say we DO go ahead and screen all competitive athletes who have either had the shots/boosters (details of which should be recorded for data/research purposes) or known CV19 infection:
If the former side turns out to be correct, we might avoid an untold number of needless deaths and/or be able to develop effective treatments to reverse or limit any damage to the myocardium.
If the latter group is right, yes, it cost a little money, but now the athletes have reassurance that their hearts are in good shape after a normal echo and EKG, and we can put an end to the debate about possible heart damage.
I'm sorry, but this is a no-brainer.