[set-digest] Back to a 3-entry, with different parameters now We used to use 4,0,9 for years. Now 3,0,6. It is slightly faster and shouldn't regress common fonts. The rationale is that OT GSUB/GPOS are split by script, so any particular script is not likely to use more than a few thousands of (consecutive mostly) glyphs. The exception is CJK of course, but those have less GSUB/GPOS work.