I also believe the shots are very dangerous and should be forbidden.
But to be fair, in this study they measured Troponin levels which is a lab marker. They didn´t find any "injuries" as you wrote, and moreover those lab marker levels were transient. Could well be that in the long term these elevated levels could result in some heart damage, but this was not shown in that paper.
RE: Evidence of Myocardial Injury in 2.8% of Moderna Booster Recipients