Hey I figured out how to get a double jump recovery (second jump recovery, DJR, SJR).
I don't think it goes infinite though. It seems to have to do with your position relative to the ground... and it's either move dependent or I haven't got the timing for other moves.
Anyway, I don't have vids, so it's pointless to tell you where to do it (I guess... it's like, slightly below half the height of Sandbag). You double jump, do an fair at the same time, and as soon as that's done, you'll be at the same height, where you can double jump again, into any aerial of course.
However the height you get from this jump is... somehow less than a normal double jump. I think it has to do with the lack of the DJ animation when you DJR (you know the wave that appears where you jump, except for Ness and Lucas?)
EDIT: This would be why you can't infinite it. Another fair will lag on the ground before you finish. You might be able to do it with uair or bair... I don't have the timing, if it's possible. Nair is also a good followup if they shielded or spot-dodged, btw. You get nair's landing lag, little as it is.
It combos well into a uair at mid percents, but I see it as a way of spacing after the fair - a hit or miss.
I just wanted to point this out, since last I heard of the ISJR for Wolf, no one knew if it worked for him, or if it would even help (with his 0-lag aerials anyway).