Queue up idea: Request solo lane or duo lane.

[TheNinjaGabe]

When you choose a character, you could hit a drop-down or something below the portrait and request whether you want solo lane or duo lane.

Maybe I want to play as Dynamo in duo lane, or Mo & Krill in a solo lane.

 

[Exemeron]

or have a swap lie in dota when waiting for the match to start