The Apply Style to Clipboard action is awesome and the Unchanged option makes it extremely flexible. Thank you!
Is there any particular reason that the Font Style does not include Unchanged in its list? If not, please consider adding that option to a future version of Keyboard Maestro.
I commonly use the action for existing formatted regular text that includes bold headings.
The way macOS works, the Regular/Bold/etc are part of the font specification.
So there isn't really any such concept of Helvetica Neue (without styles), there is Helvetica New Regular and Helvetica Neue Italic etc.
So when you choose a font you also choose a style.
There is probably ways for me to rearchitect the action to extract the style and apply it to the other font, but there isn't code to do that currently.