Horizontal frame system break loses courtesy accidentals, and how to keep divisi arrows within margins?

I attach a word doc with screenshots describing the issue.
Divisi arrows are beyond RH margin of bars.
I want the divisi arrows to end at the same right hand margin as the rest of the bars.
In my example score, there is a key change at the divide.
If I do it by adding a horizontal frame and a system break at that frame in order to fit the arrows within that frame, it works for the margin BUT now there are no courtesy accidentals at the end of the previous system.
How do I change a system width so that choral divisi arrows are within the page margins?