Are there a limit to how many Fraxel Restore one can perform with 4 weeks in between?

40yo treating acne scars with fraxel restore. Did 7 session one month apart with increased settings. I still see improvement with every session and I still see left scare but way better than before for sure. Can I continue until satisfied or there is some side effect that might result for too many fraxel. Is there a thing as fraxel performed too much/too frequent? Also does fRaxel restore tighten the folds in the face, such as those in nasolabial folds and dimple area?