At least this is a problem in Vue 2.

See this topic on Stack Overflow

The eventname should probably be something like on-select.

My workaround: Just bind to a click, mousedown or other event and set selected property from there.

Picnic CSS uses a neat trick to avoid having to specify explicit colours for elements that change on hover (see also the docs). Basically, you use an inset box shadow with a partial transparency value.

This way, I could include natuive css as-is and just specify my ow

The extension adds a few TypoScript options to lib.contentElement which should be explained in the documentation. How to specify those options per column should also be mentioned:
https://techblog.sitegeist.de/responsive-images-with-typo3-8-7/#comment-4