Tailwind hover class not supported?

Hopefully simple question: when editing a Builder “Box” component in the visual editor using the JSX editor, I am trying to add the following tailwind class: hover:opacity-80. Upon saving, the class gets changed to just opacity-80, which is not desired. Are tailwind hover classes not supported?

A slightly unrelated follow-up is that when trying to add a custom CSS class to achieve this, the placeholder global styles CSS comments suggest that using an & will scope the CSS class to just the selected component, however when following that pattern, the following CSS rule is violated:

at-rule or selector expectedcss(css-ruleorselectorexpected)

In my case, the custom style would be something like this:

& .hover-opacity:hover {
    opacity: 0.8

Furthermore, when attempting to add this class to my Box, the class gets stripped upon save. Perhaps due to having Tailwind on? I’d expect being able to support both Tailwind and custom classes