Does Ultherapy result in "subcutaneous tissue scars"?

Hello, I recently heard from a derm that Thermage is a preferable treatment to Ultherapy and the reason for that is the latter, due to the high energy 'zaps', would leave subcutaneous tissue "scarring". She says that while this is not something that we can see, it's may become a concern for the future because when you accumulate lots of those scars (via several Ultherapy sessions) you are no longer an effective candidate for thread lifts and other procedures. Should I be concerned?