An autofill suggestion - how about banking support time?

This idea hit me a few weekends ago after playing a series of games as support. Here's what happened - I was given a mid role (queued as support primary, mid secondary). After playing and winning that game, I suddenly found that I was placed into auto-fill and I ended up getting toplane (even though I am a support main??). And then the following game my auto-fill was toggled on yet again and I ended up at adc?

So, here's my suggestion - how about allowing us to bank our time when we play support?

I mean I don't mind playing support - and from what I understand, us support mains are in short supply. But here's the thing - I know that some of us wouldn't mind the option to practice another role a few games in series without getting slapped into some option where I may not have the runes/masteries setup. So how about it Riot? Can you let us bank our time in the less popular roles so we can actually work in our preferred positions and get better at them?