If you use the "folder" method as described in the OP, then yes
Before this release, the docker.img was always BTRFS, regardless if the drive it sat on was BTRFS, XFS, or ReiserFS. To make the image xfs, you change the filename in Settings - Docker to be docker.xfs.img instead of docker.img
My post detailing some items in the folder option gives one huge advantage-> If you've constantly struggled with the docker.img filling up. Performance wise, you won't see any significant difference between the options now available (But, the folder method will be faster, if only synthetically because of below)
The main reason for these changes however is to lessen the excess writes to the cache drive. The new way of mounting the image should give lesser amount of writes. The absolute least amount of writes however will come via the folder method. But, the GUI doesn't natively support it yet without the change itemized in the OP.