If any clinic offers free FG top-up within 3-6 months, then politely decline that option and ask for a discount on the primary/fresh fat graft, or an alternative FDA approved treatment of equivalent value, e.g. botox, filler, or maybe even a beauty facial or grooming treatment.
Injecting thawed fat that was frozen for any length of time is more likely to deteriorate and allows harmful bacteria to multiply (even if slowly) if not stored or LABELLED correctly. Are you sure that's not someone else's fat reserves injected inside you? Ooops!
In my opinion, a free FG top-up just seems to be a marketing ploy to lure patients back for more surgical procedures on an impulsive whim, like as if you were to pop out to buy just a bottle of milk at the supermarket, but then you end up returning home with a car load of grocery shopping! :-/