Lets Talk about roles in ranked

The system rito introduced in 2015 for ranked where u can pick your 2 best rolles is cool and all but what if you can play more than just 2 rolles but not all five . Why shoudnt you be able to pick for exaple 4 rolles (1 primary 3 secondary ).Like that Que times will be reduced and autofill wont be needed . Also why not give like 2 min time period where you can get only your primary role and after them the other secondary ones will kick in to shorten tour que time at 5 min assuming your still in que autofill will finally take over . Like that if i like say top mid jungle and adc and can play them all it'll be less likely to get stuck on supp.