I am just trying to get a test out and the only way to test it is to have sufficient tags in all posts with all clients. One client doing this won't work because the user will miss a lot of posts that are not tagged.

A service can test the idea ery quickly without modifying any client. If no one is willing to run the service, then I trully question if this feature is actually needed or if it is just a hollow feature that nobody actually cares.