will we ever get a harder difficulty of bots?

Currently there's no middle ground between Intermediate bots and Doom Bots. Offering Advanced (and actually being advanced) bots would be nice to see in co-op or the practice tool as it's a much better way to test something out or an unfamiliar champion without going into a real match and having too much pressure from other variables (map awareness, wave control, summoner spell CDs, etc)