So the way you get G2 in MoI currently is to not try to do that corner patchwork and create the G2 with the command itself..

This surface is a bit different than your original, but shows what i mean..If you create the original surfaces to be blended, in the larger surface as Michael mentions, then it can be trimmed to have a "Continuous edge". Both surfaces with a continuous edge can then have the G2 blend applied.



So note that if you open this file and select one of the surface edges, the entire edge selects. I did that for these 2 edges and ran a G2.

To get that continuous edge, you can have your surface trimming object be a continuous curve, or run the Merge command on the surface edge to combine them before the blend.