The 24-man are in there anyways.
Which means you won't be able to complete the log solo, even if you could solo queue.

I agree that catching up on the log (and the spell) is harder than it should be if you don't play BLU on week 1/week 2.
But queueing solo is not a solution for your issue.
Roulettes could be, as long as you don't let people queue for it with only flying sardine and water canon....