In my view there is no big problem and for sure not big enough to warrant redefining highway=traffic_sign and adding traffic_sign:id=* with these newly defined key partly overlapping.
What I definitely not like is traffic_signals=maxspeed + maxspeed=* + zone=end? where traffic_signals=NL:A1-30-ZE would suffice and gives all information.
So yes, for what is left of a problem I would “edit” the editors.