Perhaps it would be easier if they changed it so that all charted AD's had a discrete frequency other than 126.7. Obviously with the amount of AD they would run out so they could do what they do in some places and if there are multiple aerodromes close to each other they could share a frequency ( dependent on traffic volume).
That way, you avoid the problem of people just assuming some aerodrome's CTAF is 126.7 when it isn't, and all uncharted/ AD not in ERSA could be on 126.7 and there would be no confusion on what FQ to use.