RAIDZ2 Expansion - How to Rewrite Data for Full Capacity Recovery?

That is an official command that accomplishes the same things as the scripts that people have been passing around for re-balancing. Am I understanding that correctly?

After reading most of this post:

I think that expansion is just not fully hashed out currently. It seems to have a good way to go before it should be used. I don’t want my file sizes and storage usage to read incorrectly if I decide to resize my array.