Unilateral ptosis surgery in left eye and Hering's law in male in early 30s. Advice?

I'm concerned about developing ptosis in my healthy right eye if I have surgery. Even if the eye drop test reveals no latent ptosis in the right eye surprises are still possible. How common is this complication and how do surgeons generally handle it? Also, if my ptosis is subtle could it be better to wait until I'm older when it's much more obvious if each successive correction adds scar tissue and makes future corrections harder? This is one of the more difficult surgeries to perform.