Thank you for the introduction of Plex collections, this is a great addition. And they keep the advanced options set in Plex (sort order and collection mode)!!
It seems however that they are only visible in Infuse's Library.
On my Plex Server, I have several Plex libraries : "Movies", "Movies for kids", "TV Shows", "TV Shows for kids"..., which I favorite in Infuse, so that I can access them directly. Unfortunately, collections do not appear when I browse these favorites. Would be great if they could appear there as well.