An update -- (and thanks for asking, by the way!)
Evan finished the extra med back in March. Basketball finished, scouts pretty much winded down, spring break came and went (we just sort of stayed around home and did stuff, really low key!) ON a whole separate issue, I had surgery in the meantime, which meant much of the kids care, for a short time, went to DH. It seems to me the kids complain less with DH -- probably because he's more laid-back and it doesn't get the response it gets from good ol' Mom, lol! I also think DH does a better job at getting them settled for bed most nights, but also gets them up earlier -- different sort of schedule. In any case, DS got lots of rest during that time. So here we are now, a few months later, with 1 week of school left, into baseball season... and so how's he doing?
Evan still seems draggy to a degree, BUT new developments include very itchy, sore eyes, the occasional stomach ache, and leg pains every morning. Based on the few other tests we had run, and the recent data, it would appear he has a combo of:
(a) allergies (our pollen count is at an all-time high here, and out in the baseball fields, he gets a full snort of it!)
(b) growing pains / puberty issues.
I suppose it's a relief that it's nothing major, but at the same time, there's no real treatment for the latter stuff, anyway. We have an allergy med for him now, which helps some (but as with any med, there are always trade-offs... you fix one thing and then get 2 other side effects in the bargain!

) His leg pains are consistent with growth spurt pains (in the same places, on both legs... and he is growing at a pretty good clip lately!) I think between the allergy med and growing pains and such, he may not be getting the best quality sleep in the world, either.
The stomach pains thing I may have to accept as hereditary. My niece had them terribly, and so did DH and my MIL. At one point in DH's youth, my MIL had DH tested for leukemia, mono, anything and everything, because he was acting very much the way our DS was in March. But then, just as now, nothing concrete turned up. DH still has a "nervous stomach" as we call it. Last week we had a significant loss in our family. Our caregiver is like family to us; she and her husband are like grandparents to our kids -- well, the husband died after a failed recovery from surgery 9 weeks ago. My middle son developed intense stomach pain from that, and eldest DS could not eat for a while due to stomach pains. I think it's just their achilles heel, so to speak, that when the going gets rough for them, the stomach goes first.
To some degree, I wish I had their problem... I tend to FEED mine when I'm stressed. Ugh.
So anyway, we're just going to sort of "idle" in this holding pattern, with allergies and growing pains, unless something new develops or presents itself. THanks again for asking, though -- and I hope others with similar problems find the answers they need to get through!
Cindy