Thanks, everyone! It always clarifies the considerations for me to read other people's thoughts. I think all the posts combined have covered all the salient issues, even if only a couple actually applied to our situation at the current time.
DS is actually not afraid of losing/performing poorly or he wouldn't have taken AMC10 last year. That request came out of the blue and surprised me at the time, but ultimately I was happy to oblige him and am glad that he wants to participate again this year. However, I am concerned with DS potentially burning out and not wanting to participate in some of these competitions when/if he finally becomes competitive in a few years. I am also not so much obsessed with winning as a criteria for participation, but a strong performance has to be one of many considerations for DS' participation because I have three children, including one with special needs, and unfortunately DS' participation generally requires many hours of my own time. Then there is the issue of all his other commitments and making sure he has plenty of free time left over. I suppose that I would be more inclined to encourage his participation if I see him making efforts to improve his skills. Unfortunately, he is hardly prepping for these competitions so the only benefit is participating in the competitions, which may not be insignificant but again there are many considerations to weigh.
By the way, I do agree that a sense of progress can be invaluable in itself, which is only achievable if you try these competition before you are at the optimal skill level.
