You, sir, are a GENIUS!
I went into the MCM, turned off DynDOLOD, went into an interior cell, saved, closed the game and removed all DynDOLOD elements including Indistinguishable Billboards, opened the game and loaded the save, saved again to have a "DynDOLOD-less" save, exited, installed the new DynDOLOD v3 Resources, didn't install Indistinguishable Billboards this time, but followed up with TexGEN and DynDOLOD v3 using your video guides (no different from what I used to do but I used your preferred installation settings, with glow LODs and such), opened the game again, applied the Large Reference Fix for good measure, and boom!! It works like a charm.
Been testing for multiple hours to make sure there were no CTDs anymore, so apologies for the lateness of my reply. I know stuff like this might come in handy for whoever has a similar problem in the future.
One interesting thing that DynDOLOD notified me about during installation was to remove EVLaSS's Underside patch, since it's somehow integrated now. Maybe that was causing some sort of issue in the v2? I doubt it, but I'm glad the new installer notifies you about stuff like this now.
Once again, thank you so much sheson, you've been an incredible help!