I agree with this and am quite sure I've handled it this way in the past.

I know I've never forced a coach to sub someone out (short of them having 6 players on the floor).

Suppose A1-5 are in game. A6 is at table but doesn't provide a number of player he replacing. Ball out of bounds. You beckon A6 in. He crosses the boundary and enters court. Walks to end line for the throw in. A3 now mouths off to point you call a T on him. What do rules say you do at this point?

What's It Gonna Be Boy (Meatloaf, 1977) ...
 

A3 bench personnel: Player technical and indirect technical to head coach.

A3 player: Player technical.

It makes a difference whether, or not, he's been replaced by a substitute.

If A6 (or the coach) doesn't tell, signal or motion to A3, he's still a player in my book.

I'm just doing a player T, quite frankly, rather than apply the indirect T to the coach. If the situation is unclear, I'm going to err on the side of caution. The case play you referenced earlier applies to a fight, but a fight is sufficiently rare and the penalties are intentionally harsh that I'm not going to apply the case play to any other situation.

Wrong again. Leaving the court is not a requirement for ceasing to be a player.
The rule very clearly states when the player becomes bench personnel.

You're right, but are you going to enforce 3-3-4 in this case. Remember, you have no idea who A6 was coming in for. No one does, since it was never announced before he was recalled by his coach.

I meant to respond to this earlier and got distracted by life.

Nothing you said refutes my statement above. No one has entered the court, in fact, 5 players have left the court. What is the material error here?

Player Becomes Bench Personnel ...
 

4-34-3: A substitute becomes a player when he/she legally enters the court.
If entry is not legal, the substitute becomes a player when the ball becomes live.
A player becomes bench personnel after his/her substitute becomes a player or
after notification of the coach following his/her disqualification.

Not sure how long you've been officiating, but when I started subs reporting to the table had to state their own number plus the number of the player being replaced. This requirement was dropped a few years into my officiating time.
This made such situations clearer and enforcement simple. Sadly the NFHS opted to be less precise.

The guiding principle has to be that there are always five players, other than during an intermission or if fewer are eligible. So when a sub enters and becomes a player one of the previous five ceases to be. Yes, I would enforce that rule. I would charge a technical foul if needed.

I think you're a little older than I am, but I remember reporting the number of the player I was going in for when I played in the late 80s and early 90s. I started officiating, without really knowing what I was doing, in the '92-93 season. I honestly have no idea if it was the rule then, but by the time I picked it up seriously around 2000, I'm pretty sure it had gone the way of the "raise your hand when you foul" rule.

Did the NFHS comment on their reasoning for dropping the requirement?

I was thinking about that old rule during this conversation, but I was thinking that 3-3-4 becomes virtually impossible to enforce in the OP now that the rule has been dropped. I wonder if that was intentional?

There is no rule stating that the switch takes place at the end of the time-out. In fact, the rule which we do have states that it takes place when the sub enters the court. That's all we need to know. It doesn't matter where the five players are standing. If the entering sub steps into the court, then a change has occurred. If not, then it happens when the kid does step in.

If the sub Fails to report who he is going in for the case play stands for the proposition that you assume the worst for his team. He failed to report so we are directed to assume A3 was the player coming out. Bench personnel at time of T. I agree fights are rare but I think the play tells us what to do if we don't know who sub was coming in for.

In the other example I just tell the coach somebody, one of A1-5, has to come out because the sub became a player when he legally entered the Court. At that moment one of those became bench personnel. I don't care who, but one needs to sit a tic. It was his player that didn't say who he was subbing for. I don't think a coach would make a big deal out of this. I think he'd take one of them out without an issue.

If you allow A6 to go back out instead of one of the other players I think you are changing the rule saying that he became a player when he entered and the other player became bench personnel. You are saying he becomes a player when one of A1-5 leaves court and only when one of them leaves court do they become bench personnel.

As you said earlier, it's theoretical really.

No, I'm acknowledging that A6 became a player when he came onto the court. I'm just saying we have no way of enforcing 3-3-4 if we don't know who he was supposed to replace. I have no interest in enforcing a rule that was rendered unenforceable by the NFHS change many years ago.

My hypothetical case is meant to determine how committed you are to the rule. Nevadaref is clear that he would call a T if the coach did not comply. He has earned himself a reputation where such a T would likely not affect him. I can't say the same. If I could justify it by rule, I would do it, but I can't get there.

Last comment for me...I think. A6 became a player, you have acknowledged. The other end of the rule says the other player became bench personnel the moment A6 became a player. One of A1-5 became bench personnel. I guess I don't understand why it bothers you to say "coach, somebody has to come out because when A6 became a player somebody became bench personnel. The coach sent A6 in for somebody, didn't pull him back, let him enter and go to end line throw in area. I'd say coach it's too late to simply pull him back. I don't think coach would give you hard time. If he did over this there would likely be other issues. The rule clearly says somebody becomes bench personnel when A6 becomes a player. Take care.