I think any amount of “buildup” there is negligible though. The openings to each movie after a tilt down usually aren’t exciting at all. Ominous or mysterious, sure - which is what the tilt down to Kylo’s jumping into frame would be - but I think the difficulty of getting to Exegol isn’t really an idea that needs setting up beyond what comes later.

The idea that it’s at all that difficult to fly to Exegol is completely blown apart by the events of the film no matter what: The film goes out of its way by the climax to point out it’s not really very hard to navigate the path there at all (since roughly 5 million ships keep popping in and out of the system going both ways) - the real hard part is knowing where to go