I have an active halfmoon myself. He will follow me around the room all the time in his tank. When I'm playing on the computer or watching TV he will roam around, only resting for a moment before exploring again.
What the side effects are, I couldn't say with certinaty, I haven't read about it negatively affecting growth. Only that some fins are delicate and will sometimes tear under heavy swimming.
Victor hasn't torn any fins at all. Even if he did, I don't know how to stop him from swimming excessively, he is a fish after all. I suppose one could downsize the tank to prevent excessive swimming, but if he is utilising the size of his tank by exploring and swimming around, I would imagine it is cruel to stop him from doing so by putting him in a smaller tank.
I guess all you can really do is monitor him. His health and condition of his fins, and treat accordingly if he ever gets torn fins or fin rot. Make sure he has rest spots at different heights and places. Live or fake plants are good for that.
The rest just comes down to personality, and who are we to try and change how much our fishy loves to swim or not ^^