I see the lvm2 package is included during installation and you have automatic LVM partitioning but the native Ubuntu installer (server atleast) supports custom lvm creation using xfs within lvm, and not ext4. This is a real sore spot that lvm is ‘sorted’ supported. It would be full featured to support lvm within the default partitioner. Thank you all!
This isn’t something we as a flavour have control over. Suggest raise this on github