I would have left a comment in the polls but there wasn't enough room for what i wanted to say :)
Generally the rule serves as a COURTESY that we as TDs request from the players, and we try to be appreciative of it.
I obviously cannot speak for everyone, but if someone sets a table outside of the requested block, it usually means they're not familiar with the rule. I will ask in lobby if it's ok with his/her opponent (who usually IS familiar with the request) to play at this different table, and then mention to the new player that we tend to keep tables lumped together to make them easier to find. Invariably, that player never encounters that issue again.
I am obviously in favor of the rule since it serves as a benefit to TDs, but perhaps there is a compromise:
First, make it so that each league can designate their own preferences if adequate staffing is present to do so (by that I mean that I assume the PLD would set every pogo league without an HA to the same setting, then once a league gets an HA that person can choose). Then, if the league does select to clump tables together, state exceptions that would allow the match made outside of the clump to be completely on the condition that it is rectified by the next match/tourney. Emphasize that it is a courtesy to TDs and that continuous disregard of the system in place will result in appropriate disciplinary action (whatever corp deems that should be). Stress that TDs should continue to show amiability on first offenses and should only resort to notes/dqs if blatant and/or belligerent disregard of the rule is shown by the player after multiple offenses.
Think this could work?