BekolBlockage,
Is the driving factor before bringing in a change to a procedure the FMS coding? I understand that changes to an RNav procedure, with lateral changes, might need "it to be in the box". However changing a FL130 vertical constraint to a FL110-130 window could surely be done by Notam in the first instance, backed up by a plate reissue and finally by FMS coding. After all, anyone flying the 'old' procedure would still make the requirements of the window by being AT FL130.