🚀 go-pugleaf

If you use the -ms macros, you will indeed get a page break
between the 2 column and subsequent 1 column text.

If you use -mm, there is no page break but neither will
there be an attempt to balance the 2 column section.
If the 2C text first column doesn't reach the bottom-of-page
trap, you'll get a blank space where the 2nd column would go.

Everything works correctly if you used the -mpm macros.
-mpm dynamically invokes a compose-time program (pm, for
"page makeup") which is an expert-system of sorts for
column balancing, figure placement, etc.

-mpm and pm are on the DWB 3.1 source tape. For documentation,
see followup to article 5442 below.