There are a few other issues this reminds me of. One is that in treating the bases of psychic powers, the Buddha says that not only can he manifest his mind-made body in other realms, but that he can also manifest his physical body in those realms. In the former case, people could say that it refers to an out-of-body experience, or some other more mental phenomenon. But it’s not as easy to make a similar claim about manifesting the physical body in other realms. There are some matters like this that are harder to reconcile without some supernormal explanation.
Another thing I’m reminded of is that in later Buddhist texts like Mahayana sutras, there is a tendency to use very long spans of time, like 84,000 kotis of nayutas of asamkhyeya kalpas (and it is often “translated” that way in English). This also is relevant in descriptions of the bodhisattva path, because canonically it was said to require three limitless eons of practicing the perfections. This became awkward for Mahayana texts. So later basically a lot of the time requirements were hand-waved.
As far as ayu is concerned, is that always translated as lifespan? Is there some close relationship between that and vital breath, as though developing the bases of psychic powers enhances the vital breath within the body? As in life, heat, and consciousness? Beauty, pleasure, and strength are all things related to the strength and health of the mind and body here and now, whereas a lifespan is a more abstract concept arguably more related to some event of death in the future.