You have to give mastering plugin more "headroom" to work. Your source mix is too loud. Turn it down 6 to 10dbs, pick the Master Plan preset you want and then slam that limiter hard right - that is when the magic happens. 😎
I think Ozone is better for applying each specific mastering tool in depth and detail. I feel Master Plan is more for pushing your master pretty hard while maintaining the original (or a similar) tone and without oversaturating the whole thing. With that said, I feel like it depends what you're looking to get out of the plugin; I personally have yet to find another plugin like Master Plan, so as of right now, I do feel it's worth the money.
I usually split my masters between two limiters. Would you use this limiter as a last plugin in a mastering chain? Or maybe follow this up with a Fabfilter L2?