after much troubleshooting and googling every potential fix that people have reported, nothing worked.
I now seem to have (so far) stopped the game from crashing.
There's an option in the advanced video options where you can disable or enable "GPU memory restrictions". this is enabled by default. I disabled this.
the description text reads that disabling this may cause instability in the game but so far it seems to have done the opposite for me.
maps where i encountered regular and quick crashes now play out without crashing.
i'll keep trying to see if this has completely resolved it for me, but so far so good.
