Great! Yes you can use minnowsupport tag but don’t use it as your first tag. The first tag can never be changed because it is part of the url for the post. Maybe you can acknowledge the minnow support project in the post at the end and this will justify the tag. The first tag should be specific about the content of your post. If it is about photography, poetry, cryptocurrency, etc. if you are not honest about tags you can be flagged because it could be considered spam. It will also not help you to earn upvotes.