First of all best of luck with your hair transplant! You deserve the best having helped so many people.
I have a question for you as I am somehow in a similar situation I have got two HT with around 5500g so far. I am 40, I take finasteride and I have approximately 2500g left who would solve my problem once and for all with density around 40-45g in all the head, BUT they are the last grafts I have. I am confused on whether I should take the final step or keep the last 2.500g (my density now is around 37g average) for the future in case something happens even though I am on finasteride.
Have you thought of the above? Have you decided to give all you got, having the risk that something may happen in 20 years and you wont have grafts available?
I am interested to hair how you tackle these thoughts, taking into consideration you also don't take finasteride.
Many thanks Melvin!