Subtle lip filler yay or nay?

Hi all! I'm 36 and have been getting Botox for the past few years in my forehead (real strong forehead muscles) and 11s. I recently had my Derm try a lip flip on me and I did not like how it changed the look of my smile but I did like how it looked at rest. I have a very thin upper lip and my Derm mentioned she could instead try doing a half syringe in my upper lip of a more natural filler if I would like to try it out. I'm scared of opening a can of worms and starting filler when I want to age gracefully and mostly naturally:). I'd love to hear people's experiences with subtle upper lip filler and if it was worth it. I'd also love to hear how long it can last and if there is migration?