⌂ Broken TextSpan for gradual tempo changes on page turns

If you have a tempo change like a ritenuto or accelerando over a system and a page turn, the text on the next page is in parenthesis.
An added level of difficulty is understanding the order of the text in a broken TextSpanner in relation to the code.
Furthermore, a null value, or string with a space (" ") added to the 2nd text right-broken.text overwrites its default value right.text.
And this is especially more common and probable in scores with fewer systems per page, e.g. orchestral scores, music for band.
See Gould, Behind Bars: "Indicating continuing tempo change", page 185.