yeah, what's he got to lose. let em go I'd say.
This is a problem with two people I know down here in SoCal. Theirs are a bit more mature than 3 weeks but definately not big. My buddies biggest plant is 18" and is deep into flowering.
I have no clue what to do. I think next year I will put mine out in mid May when the sun is well beyond 12/12 and rapidly expanding.
If you are not at max sun exposure from sunrise to sunset which is like 13/11 right now...it's possible that the little sun you are missing is creating a 12/12 light cycle.
50% of mine are flowering too
I'm new to the world of internet growing so I don't know if this is a common problem. But I know of more than a few other cases on this site.
edit- I'm in the "do nothing" crowd. These plants will find their way. Let them be unless something life threatening is happening. Always plant more than you need that way if 30% of your grow doesn't work out it's no big deal.