Issue with stop position in insert mode

I found a situation where the stop position does not prevent modification past the red line in insert mode. Let me explain using an example.

In this example, I wish to move the selected E out of the C/E chord into a single note between the C and the G (thus also moving the G one quarter note to the right). As I don’t want bar 2 to be affected, I put a stop line at the beginning of bar 2:

With Insert mode active, I select the E and then press Alt + Right Arrow to move it out of the chord while pushing everything else from that point up to the red line. Here is the result:

As one can see bar 2 was modified.

However, increasing the duration of E (Alt + Shift + Right Arrow) instead of moving it behaves as expected:

There are some inconsistencies with editing operations and the stop line at the moment, and this is one of them. This is something we would like to address in future.