I agree with you it should be free and put into reasons but you can't beat $20 for such a tool. Most all of these Rack Extensions available at the website most people own already. Plugins for other programs such as Ableton, Logic, Protools and Studio One for instance. As for this particular product I have to say it's cheep compared to something like Iztope Ozone which it not worth it to me. There are other standards like ITV-R B S 1770 and EBV R128 for broadcast and film that are not included which would be perfect but more expensive.
I normally bounce down the tracks and open them in another programe because I have all these tools available to me to mix and master with RMS levels already.
I will buy it for just $20 because it's cheep and I can monitor each track independently.
I also helps the makers pay attention to what to push out for Racks by sales. What's hitting and what's not.
One thing that surprises me is that Reasons don't have a built- in stereo spectrum analyzer unless I'm missing it? I'm sure that would be the next Rack Extension or maybe in a future upgrade.