Thanks for all the follow-up help with this issues guys!
We've found the solution:
It appears the 1.11 version of the Inspire Firmware did not allow downgrading by default as previous iterations did.
However, there is a workaround.
Simply create an Empty File with no extension with the name:
For X5R camera - WM610_FC550R_FW_DEBUG
For X5 camera - WM610_FC550_FW_DEBUG
For X3 camera - WM610_FW_DEBUG
Place the empty, extensionless file along with the desired Firmware Downgrade .bin file onto the MicroSD card and wait 40 minutes for the downgrade. The other cool feature of this DEBUG hack is the ability to downgrade multiple versions at once. So you can take your Inspire from FW1.11 straight to 1.08 in a single go.
Hope this helps some others!