Charging was successful using the Manzanita Micro PFC-40 off-board charger! I was able to dial in the correct top of charge voltage and watch the SOC climb from 86% to 100%. I can definitely charge faster (i.e. provide more current) than the capabilities of the stock on-board charger even at Level 2, but the cables running to the battery aren't rated for much more than the system they were designed for could provide, so I intend to keep the charge rate right around 28-30A, or 3kW actual power into the batteries. Still, this should improve turn-around time at the track after practices and allow me some more flexibility for charging locations. One of the worst things to be dealing with between sessions or before a race is trying to find a place to charge.
Here is the little dongle that connects the charge cable connector on the bike to the Anderson SB 50 connector on the output of the Manzanita. I replaced the Anderson Power-Pole connection on the bike with a two-pin Deutche connector that's now used in production. It's just a better connector all around. The Manzanita is plugged in a 220Vac / 30A outlet similar to what you find at tracks for RV electrical hook-ups.
And here's a shot of the Manzanita on the seat. The dongle is fairly short, so I may need to extend it as this is a bit precarious with the charger balancing on the back of the seat...
While this worked out well for me, I would just caution others that this would not be something you'd want to do if your bike was going to be used for street duty as well as you lose the convenience of "plug and play" J1772 charging.