As impressive as it is, what good do those types of moves do a warbird?
Nothing, I think.

I am not so sure. This looks like it might be a "vectored thrust"
demonstration and I have read of a lot more effort being expended on
that--but I lack the imagination to think of all the reasons that it could
have value. About all I can suggest is that, if it does not reduce the
maximum speed of the aircraft but does reduce the minimum speed, that would
increase the utility of almost any aircraft...

However, it did appear to expend a lot of power to accomplish what it
did--and was probably VERY lightly loaded.

Peter