I’ve managed to do it!
I’ve simply created a “Content” Folder directly in my Plugin Folder (in the Unreal Project I’m building it on & via windows explorer).
Then I copied and pasted the uasset I wanted in there (still in the windows explorer).
Then I packaged the Plugin. Then I added the plugin to a project and went to the content browser.
I checked the option “Show Plugin Content” and tada, my content appeared (I just tested with flat .wav sound files, I hope it works for Blueprints as well :p).