I am running the Gate to Sovngarde collection for Skyrim, plus some few other mods to tailor the experience to my liking. One of those is SkyPatcher (and associated mods). I installed SkyPatcher's last version, which attempted to fix this issue, but the game still crashed after wandering a bit in the Reach region.
I installed the test DLL but haven't roamed in exterior cells long enough to know if it worked. I had, however, a crash a couple of minutes after exiting Markarth, with references to DynDOLOD - don't know if
Here it is, in case you want to have a look: https://pastebin.com/fTTBQDet
Thanks