Next I followed most of the steps from article #1 above and replaced my hard drives one at a time to ensure the boot volume was properly migrated. However, this lead to several issues:
The 2.7TB were not accessible even after resetting drive protection mechanisms, both from the v2.x interface and the command line.
Removal of the partition forces a new partition, once more only 2TB in size but no way to configure drive protection.
Following article #2 above did not help much (tip: only follow #2 if you feel very comfortable in Linux and specifically LVM commands).
v2 of the firmware for an ix2-200 only supports 2TB partitions.
So, I decided to upgrade the firmware of the ix2-200 to that listed in article #3 above. This worked as described using the firmware available on that page. However, I used article #2's instructions to wipe the hard drives of ALL partitions while they were in the Iomega ix2, saving me the need to remove them. It took two tries (as described in article #3 above), but my ix2-200 is happily rebuilding with a full 2.7TBs of disk space.
I went one step further and upgraded to v3.2.6 of the firmware via the software updates screens.
Now to copy everything back to the ix2 with more space than I had before. This is a vast improvement and will allow me to free up some primary SAN storage for other things, like building out my vCloud environment.
But before I do that, I need to finish cleaning up the environment.