Recommended synergy champs during champ select.
They should add recommended champs to play after a player on your team picks a champion during champ select.
So for instance, if you are in champ select and the first pick selects say Ivern then near the bottom it would automatically pop up the recommended champs that go well with Ivern like say Rengar. Or if say second pick selects Malphite then the recommendation at the bottom would update with say a Yasuo. Or say you playing Caityn and it would recommend Leona etc.
Also it could recommend counter pick champions as well. So it could have a counter suggestion just above the synergy champions suggestion line. So if say someone picks Vayne and it would have Caitlyn as a counter champion suggestion.
It would be a good feature to have since a lot of people don't synergize with there teammates often even when you show them your pick intent or if you ask your teammates to pick a certain champion or champion type they refuse stating they rather play what they feel like playing. And even if they choose to pick your suggestion they end up not being good at it since they are not comfortable with it.
But with this feature it would at least allow players to know what champions work well with the ones your team mates have selected which will help them make an informed decision when picking there champion. Or when picking against the enemy team champion. And people tend to listen to official suggestions rather than their teammates so it will give them a better sense of what works well together rather that just go with what they feel is right. It will also allow them to stay aware of what champions may not be ideal against the enemy team so they don't lose lane as hard.