Bettermaker have been around for some time now, but with them being so far ahead of the curve with the completely automated analogue design, the audio world took some time to truely start paying attention. And by that time, they have already released quite a few well-regarded and great sounding products!
As the name suggests, it’s primarily intended for mastering purposes, so use it on your stereo mix stems. If you’re after loudness, the clipper will make you grin (it’s almost like cheating if compared to software tools) and if you’re after depth and transparency, use it in the MS mode with fairly short release settings. Last but not least, be sure to give the IREL - intelligent release a try if you want some vibe and movement.