So you want to add the frontend styles as editor styles (for Gutenberg)?
Editor styles are indeed automatically post-processed by Gutenberg,
this is not the case when injecting the styles directly by bud (not sure about whether bud does this by default for HMR styles). For development it can make sense to add post-processing to the injected styles to add the necessary editor-styles-wrapper (the currently used style isolation mechanism).
Also this blog post about HMR and the block editor may be relevant: