@barbarabeeton re the third instance of fleqn: yeah, but I figured it's just there to prevent anyone passing fleqn to the document class lipics itself:
```
\def\lipics@opterrshort{Option "\CurrentOption" not supported}
\def\lipics@opterrlong{The option "\CurrentOption" from article.cls is not supported by lipics.cls.}
\DeclareOption{fleqn}{\@latexerr{\lipics@opterrshort}{\lipics@opterrlong}}
```