Hi Fred, I don't mean to trash the way RCOS do things.
There is always theory vs practice and there are many, many, RCOS scopes that show their way works fine. I sure would be happy to have one of there scopes so I don't mean to bash it by any means.
I think what got me going was the description you posted from their literature which said 'a secondary mirror focuser is required for optimum optical performance'.
I just don't see how when they are actually using it to adjust the BF to the focal plane,not move the focal plane to the mirror sets real BF.
It's academic really because if you follow their instructions your not going to complain about the results, I wouldn't and it seems neither would you
Jason