The plugin does a lot of work on the initial render because it has to parse and compile the theme.scss file, extract the variables, inject them into antd's theme file to generate an SCSS theme and make it available to the locally running app. The good news is that this should only happen again when you change the theme file, so it should not affect future re-compilations. If that's not what's happening, there is a recently filed issue about it where we can get to the bottom of things.