One more thing. I may have said this before - in that case please forgive me for repeating, but I advise strongly against introducing "inconsistencies", i.e. when some given feature can behave totally differently under different conditions.
The Focus flag is one of those things that can behave very differently in GTDNext, especially for scheduled items. Usually, the Focus flag means "this item is also visible on the Focus list". But for scheduled items this is not true. It is not visible on the Focus list even if you mark it as such. It has a more convoluted meaning, one which in itself is good, except that it makes the feature inconsistent. For a scheduled item the Focus flag allows you to pre-program an intention that later, when the task is on the Next list, it will at that time also be on the Focus list.
Although it is good to have that option, I think it is unwise to make double use of the Focus flag for it. There are so many other and better ways to show people these "new" tasks than to be able to set the Focus flag manually for them. One is to simply show them in Focus by default - I think people generally want to see them. Or make it a user preference to do so. Or, if people really need this option on a per-task basis, provide a separate feature for pre-programming focus and allow people to use that feature in a consistent fashion under all circumstances when such pre-programming could be relevant, not only for scheduled tasks but also, for example, if immediate focus is desired for a sequentially dependent task as soon as the preceding tasks have been completed. The underlying need would be the same under those conditions.
Also, it is a great pity not to be able to focus a scheduled task in the normal sense whenever you have decided to review or double-check something about it later today (to double-check or verify the date, for example). This "normal" focusing function ("show on focus list now") is lost when the feature is "hijacked" for the other pre-programming purpose. And you definitely get an element of confusion when it behaves differently, unexpectedly.