There is problem with bonus "Increase Tower X Efficiency to Enemy Y" - it can appear with enemy type, which is stopped spawning or will stop spawn. This is big problem in daily quests, because it's just useless bonus. Many DQs has this restriction, and it creates many useless bonuses in bonus poll. (Also there is 1 dq with "boss" type, but there is not bosses, but it's more map problem) I think this is bug, because bonus do not give enemy type, which is not present in portals (Like, you will never get "increase Multishot efficiency to fighter", if there no fighter in map portals)

I think best solution will be just not add this bonus in poll, if target enemy type is limited by waves. There is many DQs, where enemy stop spawns in early waves. If there global limited waves (currently there is no levels like this, so it's for future), then it must check that last wave for enemy type == last wave for level and allow it in the poll.