I
think (without looking it up) you were already past the generalising of non-notable historical figures when you laid it aside, which probably was the biggest single thing in worldgenning (can't think of a similar game-time abstraction).
I play on an old machine (out of habit... the hardware still works, and nobody else'd want it now) and though I tend to cut down from the 1050-year history I
still go for max-sized worlds (and actually customised for increased intra-cavern layer numbers, though that itself only matters during play/saving) without turning anything off, and activating seasonal saves (always the biggest 'lagger' during play, but might even get me to stand up and get an unhealthy snack rather than unhealthily stay seated for too long).
FPSs
* just aren't an issue, IMO, rather than an FPS
** where you're trying to dodge grenades while rocket-jumping and either crame-drop or intermittent pauses would be painful even against similarly throttled single-player AIs. YMV, but I spend so much time paused in micromanaging, tweaking and checking things that going to single-digit FPS really is not a problem for me, I probably don't notice most of the time.
If you've got a new 'high end' rig then, apart from the core thing, I think you're probably laughing. Turn things down
after your first reacclimatisation,
if you find your experience unsatisfactory. (You'll first have a Worldgen or two to make, and that'll be your first opportunity to see if it dawdles at all, and if impatient you can always halt it a century or three earlier, right?)
But I can only speak for how I'd handle it, obviously. As for you, I only can hope you have fun. And, if possible, ‼FUN‼
edit: When I wrote it it I swear it wasn't confusing, but *=Frames Per Second(s) and **=First Person Shooter... for future readers' inflrmation, if they need it.