[mixedCase]

I've seen this once across many Go codebases, it was someone who even a year in writing Go still refused to consistently name constants and global variables without snake_case, among other similar behaviors.

Support for allowing configuration of such a thing would be a misfeature if I was to be asked.

[mvdan]

gofumpt will never have formatting knobs, following gofmt's design. But if one of gofumpt's rules forbids a style which is reasonable even if it's not very popular, we might want to make the rule more conservative or remove it entirely.

[preseinger]

man you can't let snake_case pass code review