propagate is being used by ::dumper::propagate.
propagate is being used by ::vgcode::dump-geometry-grid, ::vgcode::dump-geometry-pack clients.
Example 3.66. ::vgcode::dump-geometry-grid using propagate
...
# Propagation
if !\
[grid propagate $target] {
append o \
[dumper::propagate grid $ta_name 0]