Well part of the reason we have separate role SR should help. I’m in bronze so can’t drop any further but for example when flexing you’re basically queuing for all 3 roles at the same time. It’s no different from normal except if you now queue for all 3 roles you get rewarded.
This just helps incentive people to queue in all three roles. Yes I know people will throw but let’s be honest, these are the sorts of people who would probably find new ways of ruining other people’s games regardless of the system in place.
This isn’t a stick to punish people but a carrot to incentivise flexing.