It really just depends on your ultimate goal.
If you want to be a strong candidate for an RN flight job - true paramedic credentials AND the field experience may set you apart.
Otherwise, most flight programs require 3 - 5 years of GOOD ED or ICU (both, are a plus) experience and some of the alphabet soup. Many require more of the alphabet soup and Board Certification after hire.
Keep some perspective - the RN shortage is real and has trickled over to the flight area in some markets.
I know of no other way than medic first. I also know that although I may have the RN and the experience, I remain a medic first. I've known a lot of medics that went toward the light (of $$$$) that nursing offers, but I cannot think of ANY that find nursing BETTER than paramedic.
NOBODY will pay me any more for being a medic/RN.
Finish school. Get your paramedic. Get your RN. Work really hard for 10 years and you can PICK your flight job.
Good Luck