ORIGINAL: Whirligig Alan, I tried both methods for twins i.e. using A9's twin engine setup and your P.Mix instruction for mixing Ch 3 & 6. The latter worked best for throttle response and motor trimming but the Throttle Lock feature does not work on 2nd motor on Ch 6. The former has no motor trimming and there's a slight delay in the 2nd motor on Ch 6 from zero to low throttle. The delay is less than a second.
I have each method set up on its own model so I can try to solve the throttle delay with the twin engine setup and the Throttle Lock issue using the P.Mix setup. None of these issues I found detracted from the Tigercat's flight performance. Throttle response for hovering a twin engine foamie is kind of neat. The lack of Throttle Lock on Ch 6 is a safety issue. Whirligig