Don’t know if this will help, but my similar problem was solved by turning off multithreading (I don’t know (a) what this is, or (b) that my system had it turned on in the first place)!
Link to the thread on this forum is Workaround: CTD at 87% - Loading world - Multicore Problem AMD Threadripper
Best of luck, and I hope you get in to MSFS 2024 soon - I fully understand your frustration, as it took me a full week before I could even get to the first screen - previously I was part of the “97%” club, and I then somehow got transferred to the “86/87%” club.
Regards, Alasdair (aka FlyBasher…)