I was just trying this out tonight on the DX6 and found the same problem when powering up with the Throttle Cut engaged. Not exactly what I was hoping for. I could have save myself some time by watching this first! This is really something they should figure out.
I believe you can fix this problem by setting the throttle cut percentage to -130%. I'm not sure if that value was accessible when u made this video. But setting my remote to -30 gave me issues with the throttle cut. Setting it to -130 gives me no problems at all. Regardless of the position in which the throttle cut is at when I turn the aircraft on.
Thanks for the video. I understand about what would happen if you turned on the tx with the Throttle Hold on and set to -30%. So, I'm wondering, if you set it to 0%, would it matter then if your throttle hold switch was on when you turned on the tx?