Silver, surely the benefits of any industrial technology park on the old LHR site would only as part of a 'Heathrow Garden City' idea if the new airport was still sited west of London somewhere further west along the M4 corridor?!
The only reason the technology companies are there is because of the proximity to LHR, if that were to close and a new estuary airport opened then the technology park would need to be in Kent, not Middlesex.