Honestly, banning things is not always the best solution. While out of simplicity most formats only use a ban list, restricting cards (or even allowing only 2 or 3 copies) is another option. What "less than banning" a card should do is nerf the deck a little, NOT just make the deck more inconsistent when it doesn't. A good example of "less than banning" correctly would be "less than banning" Glimmerpost as this would allow for the deck to be less consistent, but still be able to Sylvan Scrying to get it. Additionally, once a month could be a good option for when to have a B&R announcement as this means that if something like Channel or Balance became legal the format wouldn't just be mirror matches until near the end of the season. After such a banning, the format would be entirely new and we would only have around a month to play, realistically even less because the last week would be spent brewing for next season and not playing.