Did navi-computer technology dramatically increase between Ep. 4 and Ep. 9?

Question

In the original Star Wars film, Han Solo pointed out the significant lag between requesting hyperspace jump data from the computer and actually receiving it. 35 years later (in-universe), Poe Dameron, using the very same ship, engages in so-called "lightspeed skipping", dropping in and out of hyperspace at the flick of a wrist, apparently unfazed by the idea that he might "fly right through a star or bounce too close to a supernova".

Does this change in flying habits represent an improvement in navigational computer technology over the past 35 years, or is it better explained by a difference in flying style or attitude?

• Did navigational computer technology improve so much between A New Hope and The Rise of Skywalker that Poe's skipping was actually much safer than if Han had done it in ANH?
• Is lightspeed travel as dangerous as it ever has been, and Poe is just enormously reckless and extremely lucky?
• Was Han bluffing or being unusually conservative when he informed Obi-Wan and Luke about how long the hyperspace calculations would take?

Answer 1

As badly mangled as canon is on hyperspace is anyways, it's more or less applied phlebotenum anyways. Let's take the parts separately and discuss

Current canon is that hyperspace is imprecise

There's both microjumps and Hyperspace skipping. Neither are considered easy to do (or safe), or we'd see them in use a lot more often. But they do exist

Poe was reckless and what he did was dangerous

We don't have to theorize here. Nobody seems keen on it in Rise of Skywalker and considering the Millennium Falcon barely survives, it wasn't a good idea... but it worked. Somehow. (Transcript)

FINN: What are you dong?!

POE: Lightspeed skipping.

FINN: How do you know how to do that?

[Chewie groans]

POE: Yeah, well, Rey's not here, is she?

[Alarm wails]

POE: Last jump, maybe forever.

[Klaud screams]

POE: Hold on!!!

And later

REY: You lightspeed skipped??

POE: Yeah, well, it got us back here, didn't it?

REY: Poe, the compressor's down.

POE: Oh, I know, I was there.

FINN: Every time.

REY: You can't lightspeed skip the Falcon!

POE: Actually, it turns out you can.

Calculations avoid collisions

The StarWars.com databank says this

Large objects in normal space cast “mass shadows” in hyperspace, so hyperspace jumps must be precisely calculated to avoid collisions.

Which lines up with Han's line to Luke (transcript)

HAN: Traveling through hyperspace isn't like dusting crops, boy! Without precise calculations we could fly right through a star or bounce too close to a supernova and that'd end your trip real quick, wouldn't it?

Han is probably playing it cool (it's just a pesky star destroyer, Luke. Stop whining!), but does need some calculations to make it safely.

TL;DR

Poe is likely rolling the die with his hyperspace skipping maneuvers. He apparently knows enough to make it work, but just barely enough not to get killed in the process. There's no indication the navicomputer was ever upgraded, people just seem to have gotten more reckless over time. From The Force Awakens (transcript)

HAN: Watch the thrust, we're goin' out of here at lightspeed --

REY: (SHOCKED) From inside the hangar? Is that even possible?

HAN: I never ask that question until after I've done it.

So... calculations aren't entirely necessary after all... maybe...

Answer 2

The jumps were precalculated

According to The Rise of Skywalker: The Visual Dictionary:

Poe has perfected hyperspace-skipping, a dangerous series of precalculated lightspeed hops meant to throw off First Order attempts at tracking.

(page 90, Poe Dameron)

While dangerous, there's no indication that the jumps were being calculated any more quickly than they could have been before—Poe's strategy seems to have been to calculate the jump vectors ahead of time, and hope that space didn't shift too much in the meantime.

...but the Falcon was also modified

Also from the Visual Dictionary:

Rose Tico has—with great reservation—installed gravimetric compensators that allow the Falcon to more safely execute suborbital hyperspace jumps.

(page 85, Millennium Falcon)

That Rose had reservations about these modifications implies that the technology isn't foolproof, but that the Falcon could at least use it to jump more easily within the gravity well of a planet.

Answer 3

Hyperspace isn't fully explained in Star Wars Canon. However in Star Wars Legends (Which may or may not be canon.) Hyperspace is literally jumping through space-time. In one incident Luke and Chewie ended up in an alternate reality full of monsters because of some space-time altering mess-up while using the Hyperspace. Although it's briefly mentioned, Han and Poe both agree that Hyperspace is risky and dangerous. Which could that the technology has not really improved. If you are talking about Photography Technology then, obviously 2019 CGI is better than 1977.