I've seen people hang weights, like those lead fishing weights, tied to string to bend branches. For a young plant, you might be able to use washers, then you could stack as many or as few as you needed.
I've had the same issue with fabric pots. I was going to try and make branch spreaders like the ones used on fruit trees, they kind of look like this
>-----<
and you wedge them between branches you want to separate. I haven't tried it yet because my last few grows have been so crowded I'm facing different challenges.
(edit). Nice looking grow! Looks kind of like what I'm dealing with, except mine are packed into a 2x4 tent. I've ended out doing two stage harvests to give the shadowed bottom halves more time to cook.