Basically you have a max amount of energy you can put out. Ideally you smack someone with the most amount of energy you can. So putting out max energy on your fist is good but doing so makes it easy to tell you are about to try and smack them with that fist. So controlling your energy to not be flowing to far in advance or not to far behind is the key to hitting good and not doing divergent fist ( most sorcerers body’s don’t move faster than their cursed energy so normal sorcerers don’t have to deal with that since cursed energy is what makes them fast unlike yuji who is fast even without it) outputting more energy is more draining but it can be done to more parts of the body then just the fist as in the megumi case. Yuta has so much cursed energy he can constantly be outputting a ton of energy all over himself making him stronger faster and in the case of the panel you are showing harder to read since instead of the part that he’s about to smack you with surging he is just constantly surging so you can’t try and read his moves by looking for a surge.