I used zplugin/dtrace to catch all zstyle calls performed after
"zplugin load go<TAB>":

https://asciinema.org/a/birc08xq4qa2cbl9zcwvlxvho

I attach the dtrace report. Interesting, there is only:

Zstyle -a :completion::expand::: matcher-list _matchers
Zstyle -a :completion::complete::: matcher-list _matchers
Zstyle -s :completion::complete:zplugin:argument-rest:argument-rest
matcher match
Zstyle -s :completion::complete:zplugin::plugins matcher match
Zstyle -a :completion::ignored::: matcher-list _matchers

There isn't something analogous to list-colors zstyle:

Zstyle -a :completion::complete:zplugin:argument-rest:argument-rest
list-colors val

Will I be able to target the matcher-list zstyle at
":completion::complete:zplugin:argument-rest:" if there is no test for
this zstyle during operations triggered by <TAB>?

Best regards,
Sebastian Gniazdowski