I'm a 27yo male and i can completely relate to your situation. Originally born cross-eyed, I had many operations as a baby/toddler, with my last one at around the age of 10. Now it's just my left eye has an outward squint. It's worse when i'm tired. (which is often) When I look in the mirror at this eye, the squint corrects as such - then the other eye has the squint.
Fortunately at least, my vision itself seems perfect. In fact I've never had glasses. So back then (~15yrs ago now) even though my left eye was still a bit lazy at times, things were left alone after that - granted the risks or making things worse.
But today, it has me wondering if there's been any advances in the treatment?
Please be careful, I had the surgery 3 years ago & now I have double vision, I wish I never had the surgery, I prefer the "squint" compared to this horrible incurable double vision...
I'm sorry but you need to bring these questions to a board-certified pediatric ophthalmologist that also specializes in adult strabismus. This is just not my area of expertise. My internet research shows that BOTOX injections have shown promising results for exotropia in some studies. I would find the best strabismus expert ophthalmologist in your area and find out what he/she recommends.
MJK MD