remove option "fill" from role select.
replace with option "random".
impact:
players who choose fill now can choose support. with same effect.
other players who wanted role disparity now have viable pick option. they choose random and play 20% support. whereas now they pick 2 roles and random but the 2 roles do not include support.
make players who's secondary role is support receive primary role 60% or more of time.
impact:
players who now secondary as "mid" because putting secondary as sup results in 100% support play, now use support as secondary and play support 40% of time, as opposed to 0%.