Admittedly my computer is old (got it in 2018) but it's what I got and I have been able to get a few hundred hours into Immortal empires.
My settings for unit size and graphic options keep getting reverted to small and ultra texture detail and skirmish mode keeps turning itself on in the game settings every time I launch the game. I like to play on Large unit scale and have medium texture quality. And I need to start a new campaign if the units were on small scale and I update the settings to Large, the unit size remains small even if I reload the campaign.
Battles take 10 minutes to load into and when loading out of the battle it gets stuck on 90% loading bar and I have to frantically click on the screen with the option to close the window or wait for the program to respond (this can also take 10 minutes) before I can get back on the campaign map (again probably because of my computers age).
Also loading into any campaign can take up to 20 minutes.
Currently playing a Kairos Fateweaver campaign and the game keeps crashing over the end turn 61, when it reaches faction 93/136 (i don't know which faction this is). I'm currently invading Teclis and moving to take his capital. I think it is because I have turned on the Ultimate endgame crisis spawn on turn 60 ish, and it's about to all spawn in but that is just a guess.
I also noticed that the replenishment rate will get smaller if I leave encampment stance then go back to encamp stance.