That's part of my point: these buttons are going to go away soon, so why bother much.

If the styling of spark-button wasn't right, we had better fix it, or rather make it more customizable from outside.

In the very least, could you please return `on-click="{{onThemeMinus}}"` and the rest to here, and remove the new `getUIElement` calls from `buildMenu()`? You can bind `on-click="{{...}}"` to `<a>` just as well as to `<spark-button>`.