wouldn't mind seeing how or why the Empire became the First Order either.
AGREED!!! this would make a tremendous movie.
They didn't go that route... but the whole story is told if you're interested.
The Contingency was Sid's final orders in the event of his death that played out immediately following Ep. 6.
"
If an Empire cannot protect its Emperor then that Empire must be deemed a failure. It collapses not only because its central figure is gone, but because it must not be allowed to remain!"
―Darth Sidious, to Gallius Rax
As all that played out in the next year, conveniently attempting to take out other troubling targets in the meantime... high officials were awarded knowledge of where to go in the unknown regions.
Per the name... the locations were "unknown" because they were not known to current maps due to the chaotic nature of traveling between there & here. (you have to know a hyperspace route in order to coordinate it... otherwise you're just shooting off into random physical objects)
However the coordinates were very well known by Snoke (Via Sid's prior experiments) who was already a key player & it was Snoke's people who led the leaders of the broken empire to the unknown regions to re-build the first order off of paid & slave labor & developing a new storm trooper program from k
idnapped recruited children like Fin & Lando's Daughter.
Fun story how those leaders thought they were in control & Snoke was just some guy who led them there until one day at an opportune time... Snoke just rolled in & declared himself "supreme leader" & force choked anyone who argued.
Sid used his clone Snoke & these failed leaders to build a puppet force called the First Order who would take back the galaxy for Sid. The plan was that Sid showed up in all his glory with the Exegol military, once again seeming the hero taking over a tyrannical force, Sid would re-gain the seat of ruler that the Jedi took from him by violence... (in the eyes of teh galaxy)... & he would be the once again accepted leader.
Fooking brilliant. You have to understand that military isn't enough to rule. You have to have some level of acceptance of all these people in order for them to follow you. This is what Sid's plan was.
& it would've worked if it weren't for you meddling kids.
Pretty elegant when you look at how he used his failed force to take back the galaxy & then his intention was to dethrone them to retain power at the applause of the galaxy as a whole who could easily understand that their once leader has regained his proper place.
So that's how (& why) the old empire was not only allowed to become the First Order... but was purposefully militarized with massive power by the very person who ultimately intended on taking them down, killing them all & retaining power after they failed to protect him.
This plot is every bit as deep as the prequel'z plot. Both existing as some of the deepest plots in cinematic history imo.