That’s an interesting point. Taking the Buddha’s decision that ānāpānassati represents all four satipaṭṭhānas as actually not at all talking about vipassana. 
But I understand your view - the Buddha explained that breath is to be observed as the 42nd part of the body, as the element of air (e.g., in MN 62 Mahārāhulovāda Sutta).
My point however was not at all related to vipassanā or samatha nature of breath. I have shown that the Buddha lead His students in observing the present moment already from the beginning of their practice. As they gradually trained in observing the present moment, they went through practices that did not require as much sharp mindfulness to practices that required it sharper and sharper.
The idea that we do not need to be in the present moment and that we can consider past and the future as well has been already very strictly rejected by the leading monks of Myanmar. A famous monk you know of was prohibited to publish his books just because he suggested that considering Dependent Origination with its past and future segments is a suitable meditation practice. The prohibition was based on the fact that observing the past and future is discouraged by the Buddha in, specifically, Bhaddekaratta Sutta. Or so I was told by one of the members of the committee that issued the prohibition.
