Quote - I export the V4 M4 figure in various poses and use those to make sure my scene is sized right, but that doesn't take into account other figures.

You don't need other figures.  Basically any of the standard adult human models that are most used (any of the Victorias, Michaels, the E-F) will get someone in at least the right ballpark.

The room I mentioned where a character couldn't get through the door had it too small for Miki2, which is significantly smaller than the other adult models, so that should tell you how out of whack it was.