I was not suggesting a parallel running line that would shadow the lines into platforms 1 and 2. I was suggesting that the running lines run from the area after Ardwick station (heading towards Manchester city centre) would pass on the other side of the Square One offices. This would pose no difficulty with a station site with regard to customs clearances (which is no bad thing) nor would there be any problems providing a "dead-straight" run in of the length that will be required. There should not be any transport problems on that particular side of Piccadilly railway station.
However, this is just my own view of matters, for what it is worth.
I don't imagine that the need to demolish "Square One" would represent any barrier to the HS2 station being on the north side of the Piccadilly site. It is occuped by Network Rail; so they are hardly likelty to object.
The other points raised by Nym may be more decisive though, it certainly could be difficult to get the high speed lline over the Mancunian Way, and then dive down under the lines towards Guide Bridge.
I trust we will see not too long in the future.