I tried two different strategies to unfreeze a segment using lua, and neither worked. Strategy one to deselect segment number 2:

deselect_all()
select_index(2)
do_unfreeze_all()

This unfroze everything, as do_unfreeze_all() doesn't use the selected indexes. Strategy two:

deselect_all()
select_index(2)
do_freeze(false, false)

This did nothing. I think this one should work. I can unfreeze a segment using a UI script, but not lua.

Action item:

• Make do_freeze(false, false) unfreeze the currently selected items. If either argument is true, freeze that part, but unfreeze the other part.