You can certainly use sheetworkers to set the others to 0, but I'd recommend using radio buttons for this. If you do want to continue with the checkbox method, this script should get you started: on('change:loadout1 change:loadout2 change:loadout3',(event)=>{
const resetter = {//A lookup of what to set based on which loadout was selected
loadout1:{loadout2:0,loadout3:0},
loadout2:{loadout1:0,loadout3:0},
loadout3:{loadout2:0,loadout1:0}
};
if(event.newValue*1===1){
setAttrs(resetter[event.sourceAttribute],{silent:true});
}
});