All examples of a single-stroke caesura I have seen have it extending roughly half a space above and below the fifth line of the staff. In Leland (/in MuseScore), it extends all the way down to the fourth line and the same amount upward.

Current implementation:

What I would expect this to look like:

Another example:

More examples and previous discussion can be found at w3c/smufl#108 (comment) (and the first comment of that issue); see also steinbergmedia/bravura#74, https://musescore.org/en/node/334302.

I see this notation used with some regularity in Western church music.