Multi-measure rest display and placement
When creating multi-measure rests, the rest symbol is apparently centered in the measure. This is fine when the only thing in the measure is the rest.
In the case of key signature changes occuring at the the start of a multi-measure rest, the layout is intelligent enough to know that the left part of the measure is occupied with accidentals, and will not overwrite them with the rest symbol, but then the right side of the measure is empty.
The multi-measure rest should center on, and stretch accordingly if the measure stretch property is changed, on the empty part of the measure, not the center of the measure between the bar lines. It should likewise shift slightly left or right if there are barlines that take more printed space within the measure, such as start repeat on the left side or end repeat on the right side.
The example of key change is the most drastic and easy to see. In the case of the score I am working on, the measure begins with 4 natural signs cancelling out A-flat major followed by 3 sharp signs to start A-major followed by the rest symbol, centered in the measure. First the measure needed some stretch to make the symbol appear properly, then the right side of the measure remains empty. There is no manual way to select the symbol and manually stretch it, but this feature would not be needed if the placement within the measure is fixed to reflect the available empty space.