I wish Flex Queue should have a Role Queue Equalizer option, so you have an equal chance of getting any of the roles in any game.
Sometimes, i have games where i play Support over and over and not the other Roles because the Queues are longer.
Just queue tank, then dps, then support and repeat.
I already do something similar: i will play Flex Queue then get like 4-5 Healing roles in a row, then i will unqueue then deselect the Healer role and Requeue for Flex Role but for Tank and DPS. It works pretty well, it would just be nice if there was an option to equalize the wait times for all 3 Roles.
Flex queue is just tank queue with extra steps.