Nice. Looking at what's exposed in the unicode package (did a tad bit of research [0]), there may be limited opportunities to reduce that since the structs are exposed. Maybe fewer goroutine suspend points between cpu-only tasks inside init, I dunno, not very familiar. Maybe a bunch of structs initialized with only const exprs in their fields could be eval'd at compile time and become a data section in the binary (until mutated maybe or just copied from the data section since there're no public immutable vars).
0 - https://github.com/golang/go/issues/26622