((((hugs)))) So happy that you've figured it out!!!!!
My dd2 had a huge soy intolerance, and she completely outgrew it. I started giving her trace soy around 17 months, and full on soy around 18 months and she's fine with it. I waited longer than usual because I was still nursing her until 17 months, but I add soy back to my diet around 12/13 months with no problem.
I would think you could trial around 12/13 months, and chances are it will be ok!