I think they shouldn't change. As I understand it `default_text_styles` should be the styles of the general paragraph (TextBlock). Those are then applied to all the TextBlock contents/Text elements. Those can however overwrite that setting.

E.g. when I have a para with a green stroke then everything will have green stroke e.g. every strong, em etc. in there. But if I put an fg with blue in there, it should be blue :-)