I agree with the comments above. I have been at the sharp end of this. The idea was tried some years ago at MAN by one of the locos, and did nothing whatsoever to speed up boarding. Initially there was free seating, then the current system, or something very similar, was tried, with no improvement in boarding times. Then they went to standard seat allocation, which had very little effect either way. I think it would be wiser to remember that there is a lower time limit to pax loading which can never be improved upon, no matter what they may have told you at business school.
Two sets of steps, a prompt release of the pax from the gate or the aircraft and ensuring that there is a working PIG on the stand will do more to ensure quicker turnarounds than faffing about with seat allocations,