This Agave has done some admirable growing since this post. I was quite surprised to see the roots growing out of the pot already. I am not sure whether this plant likes being rootbound or not but I thought it is still early enough in the growing season to put it in a slightly larger pot to accommodate growth.
You can see that it was not very potbound yet but it did grow a good amount of fat fresh roots that might enjoy a bit more roaming space. I just put it in a slightly larger pot in a mix of normal potting soil and gravel (about 50/50).