Mark File System Only in Standalone Viewer?

So, I finally took the dive and upgraded to Opus 12 for mainly the "Status" and images "Mark" features. However, to my dismay, I couldn't find the "Mark" feature anywhere in my different Lister's views. After watching the "What's New" video, it seems to me that the feature so far is ONLY in the Standalone Viewer? Am I right about that or it can be enabled program-wide and I have to enable it somewhere in Preferences?

I am currently not using Standalone View and never have; When I double-click an image, Picasa 3 is the default program it opens in (because I love the borderless overlay view of it). So, if the feature is Standalone view only does that mean I'm out of luck?

Marking files in the viewer adds them to a Collection. You can add files to collections in various other ways within Opus as well.

You might be able to configure Picasa to add files to collections if you can set it up to run external commands and pass file paths to them. I don't know Picasa well enough to know if that is something it can do.

Soooo, pretty much I got excited for nothing? Oh well, OK!