Clarity on Flex Que Prizes and Boons

Does anyone know the prize for both rank types? I don't want to play Flex unless im getting at least one (or more) of the following....

1: IP boost for helping Riot fill in spots. 2: Preferred role since I am a single player. 3: Proper rewards for ranking decently at the end of season.

Right now they have told us that you get victorious skin for either que, but I want to know what you get with both.

I'm not a fan of waiting an entire year to find out what I "might" be able to earn.

So if anyone knows, or if Riot is reading this could we get some clarity on a reason to play?

As of right now I'm in promotionals, but I'm not going to go beyond them unless there is a point.

Riot, will there be a point? Also sorry if I sound angry or grumpy, I just hate rolling the dice on potential prizes. I just want to know if I should invest my time or if Riot doesn't want me and other solo's playing Flex Que.