Does implant exchange to go bigger materially increase risk of complications?

Since the capsules have been made with your current implants, the risk of capsule formation is now less. The risk of bleeding is less, even if the capsules need to be expanded. The second surgery is less risky and should be much less painful.

Dear Jess9912,
breast revision surgery is the most difficult plastic surgery procedure performed. Botched breast surgery alters normal tissue planes and laxity, the ability of breasts to heal properly, and leaves scar tissue that dramatically affects the level of difficulty of the corrective surgery.Many patients come in to correct poor outcomes from their initial surgeries. The most common problems are due to implant malposition, bottoming out of the implant, poor scarring, and incorrect implant size.While the type of revision required will depend on the result of the previous surgery and the desired result of the patient, some revisions involve extensive pocket repair that may or may not need specialized external bras.If you are considering breast surgery revision, you should speak with a board certified plastic surgeon and have yourself properly assessed. Only after a thorough examination you will get more information and recommendations. Also, you have to make sure that your surgeon understands your breast augmentation goals.
Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

Because you are over a year out and doing well overall, it is unlikely that you are at significantly increased risks. Each procedure still carries some risk on its own. Due to the reasonably sized increases you desire, it is likely that you will do very well overall. A full consultation would be necessary and I recommend you work with a Board Certified Plastic Surgeon.