Scale is a bit hard to judge with just bricks in the background for size. How big do you want the tree to be? Whether to allow free growth depends on what you want. Are the trunks close to desired size yet?
One of the factors with multi trunk bonsai is that every additional part of a bonsai adds difficulty. Getting good roots, taper and good branching on a single trunk tree is difficult. Getrting all those factors on a triple trunk tree is not just 3 times more difficult, more like 9 or more times.
None of the fronts has al good points.
1 has a great place to chop the main trunk shorter to eliminate the long, straight untapered trunk but there's no obvious place to reduce the second trunk to match. Being trident that may not be a problem as they usually sprout well after chop. 2nd trunk apex currently growing in toward the centre which is not natural so needs realignment or chop and regrow.
2 has good shape on both smaller trunks and except for the tall, straight main trunk is a good option.
3 has the apex of second trunk toward the back. I'd prefer it coming forward away from any future main trunk canopy.
Orientation of 1 and 2 with unequal space between trunks is more desirable than equal distance as in pic 3. Just a little rotation can often make a big difference.
Well past time to get those props out of there. They've already made enough damage on the trunks and if those are not set yet I'd be very surprised given the callus formed around the ends of the sticks.
