Nit: there's no support for quoting in vanilla ActivityPub. The way {Ple,Akk}omas compose them is to (a) add a nonstandard field pointing at the quoted toot (b) add a `<span class="this-is-the-quote-rendering-for-those-who-dont-understand-the-field> QT: Link To Quoted Toot</span>` suffix to the html representation. So, either (a) works and (b) is rendered with `display: none` or sth similar, or (a) is ignored and (b) is displayed.
@pluralistic Thanks for the clarification.