I'm not sure we need the rostrum, as the East end of the stadium offers great elevation over an area ideal for the track (much higher than a rostrum, and very close to potential track) , and also the greatest shelter from sea breeze:
Tarmac + grass + swept dirt ??
The following photo is taken from the potential "rostrum"
The photo doesnt do the elevation or scale justice.
Anyway, let's assess tomorrow night.