Propose that the Advanced Editor (aka WYSIWYG Advanced) plugin be bundled with ClassicPress release (like Hello Dolly/Askismet are with WP - not actually integrated into core like Gutenberg was.)
Why? Since ClassicPress uses TinyMCE (Classic Editor), having Advanced TinyMCE features available makes a lot of sense... Many users don't know of the availability of Advanced Editor options, and this approach would both bring awareness of them and make them more readily accessible. The Advanced Editor is a battle-tested mature plugin inline with ClassicPress project goals, and so is a great candidate for bundling.
WYSIWYG Advanced: https://github.com/johnalarcon/wysiwyg-advanced
Discussion reference: https://forums.classicpress.net/t/should-wysiwig-advanced-be-bundles-with-core/1155/2