Like, helluva clippy on mid zoom levels.
Prevent label clipping by increasing all buffers
for the label layers to the maximum. This increases
the tile size somewhat, and we will need to optimize
the exact size at a later time.
There being too many labels and labels being cut off are separate issues. Yes, reducing the number of labels will decrease the number of cut off labels, but you can have high label density without cut off labels.
Well, the user-facing result is the same, that's why it makes sense to keep it in one place IMO. Anyway, https://github.com/nyurik/osm2pgsql-osm-bright.tm2source/pull/28 improves ordering and thus clipping looks much better. Also, it should be faster.
Data source commit: https://github.com/kartotherian/osm-bright.tm2source/commit/001d2674d0f9f6eb0dbb63347d3d9624d04b1710
Style commit: https://github.com/kartotherian/osm-bright.tm2/commit/44b464d277ee551dc3307e6ce623d40671eb5da9
Together, they improve at least Bay Area significantly for me. Still leaving the style open though because it's not fundamentally resolved.