Description of problem: Anaconda needs some UI to support LVM Thinp. The most obvious thing I know of is the need for thin pool profile selection (performance -v- snapshot). Other things that have been mentioned are support for multiple pools, specifying separate data and metadata devices, chunk size, metadata size.
Triaging old anaconda bugs. At a quick look this is still valid: I don't see any thinp-specific feature UI in custom or advanced custom.
There are currently no plans for implementation of the additional support in the Custom Spoke. Is it something that could be interesting for Blivet-GUI, vtrefny?
I could add some advanced options for thinpools to blivet-gui, it shouldn't be that hard.