Roots! Now what?
 

I know that Master Ray says to grow roots and following his excellent tips, I have done so. But what in the world does an indoor grower do about THIS?!? (See picture.)

You don't have to do anything maybe. One of my catts --- actually more than one ----- has lots of roots both inside and outside of the pot. The one that has flowers beginning to open today (at this link here) has roots growing in the shallow depths of sand/soil. So it is growing both in scoria (in the pot) and sand/soil (outside of the pot).

In your case - maybe the options are to just leave them keep growing - in which case they'll likely attach themselves (like glue) to surfaces outside the pot. Or transfer to larger pots. And, if there are space constraints - then there may be a need to somehow expand the growing area.