Imo just having cfs could cause potential issues for Mana with certain countries. I'm not sure about other places but the Aus Government is going to start targeting "underage gambling" which is going to include lootboxes, gambling of purchased game currency and stuff like that. Plus I'm not sure about other countries laws around under 18 online gambling. I believe this is mostly for games like CSGO but could apply to mana as well.
Maybe a max cubits per person (although i guess this could be bypassed with alts)