The purpose of Jim's course is to ingrain a feeling of relaxed control when you're at full draw, so that if you draw the bow and don't feel relaxed and in control, it doesn't feel right to you and you let the shot down. Through many repetitions, you have created a new habit of being relaxed and in control to replace your old habit of feeling nervous and rushed. I don't think I could go from years of feeling nervous and rushed to feeling relaxed and in control in one day. After drawing and holding many times to build up the feeling of being relaxed and in control, if you shoot the bow while feeling nervous and rushed, it's like sneaking a cigarette after not smoking them for a month. I've been through that and whenever I did it, it made me wonder if I was hooked on cigarettes again, and I had to work extra hard the next day to be sure I was still off them.
It probably is a really good idea to stay off shooting for the first 21 days, like the program says. The program allows you to shoot after the first 21 days, under controlled conditions. I'm on day 35, and I really do need the controlled conditions, because a big part of my target panic had to do with drawing the bow with the intention of shooting it. So even with the confidence I had gained during the first 21 days, I still had a nervous feeling the first time I drew the bow knowing I was going to shoot it, even at 1 yard. Interspersing many draws with few shots has helped me to dull this nervous feeling and has enabled me to draw and shoot with confidence, after drawing and not shooting a few times.
I think the answer to your question is to be honest with yourself. Your goal is to draw and shoot without the nervous urge to release the shot prematurely. So if you decide to take some fun shots while you're in the middle of the program, honestly notice whether drawing the bow with the intention of shooting it makes you feel nervous. If it does, let the shot down. If you do that, you're staying with the program. If you shoot the shot in a relaxed and controlled manner, then maybe you don't need the program. If you end up shooting the shot and rushing it, then you've just sneaked a cigarette while trying to quit smoking, and you're going to have to work extra hard the next day to get back on the program (DAMHIK).