SO here is why I think this was dumb. The bike is not on it's "resting" weight, so you don't know where it stands and sits. Weight position on a motorcycle is critical, otherwise riders wouldn't lean off the bikes in turns, so how do you know you placed your weight in the right place when you made your subframe? you don't. When real motorcycle engineers do this they use computer modeling software that allows them to move a virtual person around a virtual frame and study weight distribution before they even lay weld one. You could have replicated this with the bike fully assembled sitting on two chassis scales where you mount the bike and figure out where you need to sit. Instead, you have a bike on a block of wood held down by rachet straps and are basically hoping for the best.
I hope it works out for you, but there is a real chance you could end up with a rider position that feels like the rider is doing a continuous pull up to keep himself from sliding off the back of the bike even when standing still because what is level on a block of wood isn't level on acceleration squat or decel dive.
I thought at first the sub-frame added some torsional rigidity to the swingarm pivot to further prevent the arm from twisting, but then I realized it was so any forces being exerted on the arm would translate to the subframe so it doesn't feel like the bike is twisting underneath the rider. As long as that's maintained at least you'll have the right feel.