Boundary labels sometimes warp text unnecessarily

[ZeLonewolf]

Expected behavior

Boundary labels along straight boundaries are straight.

Actual behavior

Sometimes, part of the label is rendered crooked.

Screenshots with links illustrating the problem

In the example below, the "E" in "East Tennessee" is tilted as if it is trying to follow a curve or turn in the boundary line it's following. At this zoom, the boundary line seems to be within a pixel or so of being straight so the tilt of that character looks wrong.

https://www.openstreetmap.org/way/39087865#map=13/34.99611/-85.83833

[imagico]

This can probably be mitigated to some extent by adjusting the combination of text-vertical-alignment and text-dy - but it likely cannot be fully avoided - at least not easily.