What's your experience with setting boundary with estheticians/providers been like?

I would like to visit a medspa or cosmetic dermatologist to seek out options to treat ONLY my acne scarring. However, I'm concerned that they might point out additional "flaws" followed by options for treatment, whether because they intend to sell me more service or because they're just carelessly offering unsolicited advise. I feel this will magnify "problems" that I have never really noticed and anchor them to my mind as something to feel self-conscious about. Anyone has experience with setting boundary right away to prevent unsolicited advice/offers without sounding to aggressive or presumptuous? I plan to say something like this, but I don't know if it comes off as confrontational: >I’m here to discuss the concerns I brought. I do not want additional procedures or treatments suggested for issues I haven’t raised, and I will step out if this boundary is crossed. But since I can't control how others behave regardless of what I say, do I simply need to accept that unsolicited advise is a risk anyway?