I have the Flat6AIII on my GT71, M63 focuser thread, and the 68III on my FLT 132, M92 focuser thread. The 68III is at least twice as big and twice as heavy as the 6AIII. Can't imagine the 6AIII on the FLT132 with a M92-M63 adapter. I would think vignetting would be terrible. I also have the Flat8 for the FLT132 which is gives 0.72 reduction. It is even bigger and heavier than the 68III. Flat6AIII is less than half the cost of the 68III, so I doubt the 6AIII has as good optics. Flat8 and 68III are very solid, threaded adapter tight and accurate. Flat6AIII is sloppy in the adjustment threads. I had to do a lot of playing around with the adjustment position to get flat stars in the GT71. Flat8 was spot on with the recommended setting, same with 68III. Both of these scopes use the stock focuser.
I have had three WO scopes, and they were all very good for the price. But I think I would wait for the next release to let them get the bugs out, similar to Red Cat. Mine are versions III or IV, except for the Z73 I had. It was initial release and was OK, but was a doublet, so hard to compare to the triplets.