When to switch themes/plugins to `.gjs`?

OMG. Just when I thought I was starting to understand.

So it’s not just me! :tada:

Does this make it be a glimmer component?

And if that’s the case; even if it’s just a template, adding the class makes it run faster than if it’s a .gjs that has just <template>My important words</template>?

export default class MyCoolComponent extends Component {