I think that's probably true that an implant at the same time would increase infection risk (extra openings), but I would think with proper post-care routine it can be minimized. You'd have to keep it clean in there, which can be difficult after surgery, so a lot would be on you to do that. I'd personally take the risk and do both at the same time and have the mindset I'd keep it clean at all costs. They give heavy duty RX mouthwash etc to help with this as well, and if they don't, you should ask for it and anything else that can help keep it clean.
Your curve of spee on the left side seems drastically different than the right. This is probably your body compromising for different ramus sizes/asymmetry. It should probably be addressed via ortho prior to surgery? Has anyone recommended that?