I feel like Practice Tool could be perfect for practicing vs certain laning matchups
If you and a friend could have skirmishes with a certain champion, it would really help with laning phases. You could ask someone to help you with your farming and with learning when to harass, you could practice all-ins and learning when to make a dive and when not to, you could also learn how to survive vs matchups that your champion suffers horribly in.
You could also practice dodging certain skillshots that may give you trouble, learn about what items are the best possible start vs a situational matchup and etc. Just things you simply cannot learn through wailing on a single AI or a dummy.
It feels like a waste to not allow 1 invite to a friend for practice sessions in something that's absolutely perfect for such things.