All of the Lightsavers - maybe ALL Duck boards - use Atmel chips, so I'd think Flip should work just fine even if Duck doesn't "officially" support it. I don't think O2D Keymapper does anything Flip doesn't do when it's actually flashing the firmware to the controller. Maybe it's unnecessary for Duck to say anything official since, duh, Atmel's own flash utility is always going to work. But you didn't really explain why you're flashing the keymap that way in lieu of using O2D. Can you expand on that?
Edit: Having read all of this again, I realized you're saying Flip on Win10 isn't officially supported. That was not at all clear on the first read-through, sorry. I haven't attempted it myself, but you could try running Flip in compatibility mode if it's giving you trouble.