Disclaimer: I'm not involved in BSA, but I do run my church's boys' group, which in a lot of ways is similar to BSA.
Going off what you shared here, you seem to be doing the right thing. Have you explained to his parents that he is behaving in a way unbecoming of his position, and what he needs to do to advance? They may be only hearing what their boy tells them. If you have made any threats of punishment, be prepared to act on them. If you haven't, you may want to start, along with the promise of reward if he does well.
I do an inspection every meeting on Wednesday. They get a point for every category I can check off for them, and every quarter I give a modest prize to the boy with the most points. One of those is for dress code. Maybe you could use something like that as incentive for him to wear his uniform.
What I'm not hearing here is what you have actually done. You've been "holding him accountable." What does that mean? Sending him home for being out of uniform? Arguing? Public humiliation? Asking him to let others speak without interrupting? Specifics will make all the difference.
A good question.
So the action you took that she objects to is ending an activity and calling her to report his misbehavior?
And the action she took was what -- to complain to you that you were picking on him?
Just trying to figure it out. It doesn't sound debilitating yet.
She is not complaining to me about the situation at all. She is complaining to others on the committee and while not explicitly saying it, seems to be implying that she no longer wants my participation in the program. She's said she is beginning to think that she doesn't want to send her boys--she has two in the troop--to attend scout meetings so long as I'm involved. However as I've said before, the unit committee doesn't see the things she's complaining about nor do they see that I've done anything wrong.
I wouldn't say that it is debilitating just yet. I'm just trying to find ways that I could diffuse the issue before things aren't repairable any longer.
OK. So you ended an activity and called her to report his misbehavior.
She has complained about you doing this, to the committee.
The committee is on your side.
What would you like to have be different from what it is, or what do you think might happen that you want to prevent?
His leadership position in the church is irrelevant. Judge his actions in the troop, by the standards of the troop, and what is best for it.
That's one reason I've long argued that the Troops should not be hosted or otherwise organized by churches. But that's my own hang up with the BSA, and sadly, why despite being a scout myself, it is unlikely my son will be one.
Good luck! I'll be following the thread to see where things end up.
That does make it tricky. But it sounds like he can't advance due to his own lack of care. Hold him to the specifications just like every other boy.