Autofill workarounds
I think if you are going to force autofill on us, you should let us pick one role that we cannot be queued as. For example, you queue as normal, say Top/Mid is your preference, and somewhere on that screen are "Autofill options" where you can choose 1 role that you will not be put into under the Autofill function.
Yes, the majority of people will chose to not be put into the support role, but I don't think this is unreasonable. I appreciate that you are attempting to reduce queue times, but forcing a highly undesirable role on players is far worse, in my opinion, then have queue times be slightly longer.