Cautionary key/time signature before repeat barline if start repeat is in different key/time
I've seen in some scores a courtesy key/time signature before a repeat, if the song is in a different key/time after the jump. These signature are sometimes in parentheses because they doesn't even apply to the following measure, which could have yet another key/time change, resulting in a potential measure or system ending with a key signature in parentheses, a time signature in parentheses, an end-repeat barline, another key signature, and another time signature.
It's a rather obscure feature, and I know jumps are complex, so it's only a feature request. I'm not even sure how or whether it would be notated for segno or coda systems. However, unlike feature requests for automation/alignment, currently there is no way to even include this notation if you wanted it.
While automatic generation is possible, it would take a lot of work, and not everyone would want it. Perhaps we could make dropping a key/time signature onto a repeat barline a permitted operation to create this notation?