In order to optimize & reduce the amount of Flood Adverts sent by Repeaters, I propose that Repeaters should Auto Flood Advert in inverse-proportion to the amount of traffic/packets they see.
If a Repeater doesn't see any/many packets then it should auto-flood-advert every couple of hours.
If it's in a busy area and seeing lots of traffic then it should throttle back and only auto-flood-advert every (say) 48 hours.
The rate of Flood Adverts t should be dymamic based on the amount of traffic seen.
This has the additional benefit that new Repeaters would advertise more frequently than already established Repeaters, thereby helping with Node discovery for new users.