I think multi-language patch “comments” is more difficult than multi-language “Help files”.
M-L-Help files can be done translating each help file and saving it with a name like “metro-help-ES.pd” or “metro-help-FR.pd” then telling pd to add the -ES or -XX to the english helpfile name.
This is a lot of work, but can/should be done by the community, I remember that something like this has been done in Pd-extended menus with an online infrastructure, everyone contributed with what was left to be done.
Of course this increases a lot the size of the package, there should be something like downloading only the extra language that you use and not all. Some folder somewhere.
Just a sketch.