This is not a question. I just learned something through trial and error and wanted to get this knowledge out there in case others are thinking about the same thing.
I connected my Variax Shuriken to the Variax input on my Helix Rack and then ran an unbalanced cable from the Guitar Thru ("buffered") output on the back of the Rack into the interface as a DI. There was no DI signal as I expected there would be. I then connected my Shuriken to the HX Rack using a guitar cable (unbalanced) to the Guitar input on the front and viola! It worked.
Conclusion: The Guitar Thru output can work as a DI only for the Guitar input on the front of the unit. It does not work for the Variax input, but you can connect the guitar using both Guitar and Variax inputs at the same time to get the DI to work.
I hope this helps someone else out there.
