The 1 big possible plot-hole

I think you're missing something. While Cryonics exists today and many people are already cryogenically frozen, "Lucid Dream" does NOT exist, and is not supposed to exist yet. Lucid Dreaming does not happen right after you are cryo-frozen today. Instead, it only happens far in the distant future after resurrection and dream technology have been developed. At that point, if you had chosen the Lucid Dream option, you would get thawed out and cured but kept asleep to dream about the centuries-old world you left behind. That is, until you decide you want to wake up and live in the real world.

But if you had declined the Lucid Dream option, you would simply get thawed, cured, and woken up to live your life in the real world.

An interesting, detailed article about Cryonics -->
https://waitbutwhy.com/2016/03/cryonics.html

That's because he just died. There is no LE company. He died in the car accident with Julie. It takes a few watches to figure it out (yes I bought into the original ending idea too) but he's definitely dead. The movie like a purgatory with David ''moving on'' towards the end.