Bah.So fortunately I stumbled upon this thread that clearly deserves more upvotes on Reddit - it fixed my performance and CTD issues.
Source: https://www.reddit.com/r/MicrosoftFlightSim/comments/majv3z/i_have_possible_fix_to_the_ctd/
I have 32GB of RAM in my machine so I don't need to keep swapping and can save on hard disk space.
Then you show me this.