Paul, it’s not a “passion” more an obsession or addiction!
By the way did you know WWFF (KFF?) already had the US parks classified before NPOTA came along - unfortunately the ARRL decided to give their own format of identifier but I believe there is a conversion table somewhere on the internet, so you can most likely claim the NPOTA activations as WWFF activations as well - as long as your set up meets the WWFF rules (I guess operation from a car, while allowed in NPOTA may not be allowed in WWFF).
In any case those who have taken part in NPOTA don’t need to stop at the end of the one year special event, they can carry on in WWFF.
I have never used LOTW - is it not possible to send graphical - self print QSL cards as one can in eQSL?