Autofill hasn't reduced queue times

because people who really don't want to play support (mostly people being autofilled) just dodge when they get it, forcing you to wait for another match to be found and the time it takes to redo champion select

when a large enough number of people hate supporting so much that they are willing to take an LP hit and a time penalty, something is wrong with the game. Maybe supports are underpowered (unlikely), maybe they are just unsatisfying for most people (most likely). If its just because supporting is unsatisfying you might want to ask why.

And if you do ask why and determine that the thing that makes supporting unsatisfying for most is the very thing that defines it (the same thing that makes it satisfying for those who gravitate towards supports), then you should rethink the whole damn thing. If there aren't enough people willing to play support because its too "supporty", then there isn't anything you can do to resolve that aside from opening up another route / option.

In other words, making a new support champion aimed at those players wouldn't fix it. Making new support items for players who want a slightly different experience wouldn't fix it. There is no world in which supports constitutes 20% of the champions in games that works if not 20% of the playerbase is willing to play in a "supporting" style. Most people don't want to experience their success through others, they want independence, and that is antithetical to the whole premise of a support.

In other words, either queue times will be long, champion select will churn, or you will retune items and champions to widen the lanes to different combinations of champions or roles so that a "supporting style" does not have to make up 20% of the styles of play across the game. And you'd have to do that without making it impractical for players who want to play a very "supporty style" to continue playing in that way.