Being serious for a moment, Warton is not an operational Tornado base, it's a company airfield. The budget for CT is going to be tiny, all flying from there is going to be on company business.
There is a standard flight test technique that is used to determine combat performance - that is the ability of an aeroplane to turn continuously at best rate in a dogfight. This involves timed acceleration in full dry or full reheat at a series of altitudes from as low as practicable to as high as practicable. This would be consistent with the selecting full reheat at sea level and a slow 200kn or so.
Just guessing, there are other tests - perhaps measured fuel flown in combat or take-off power at sea level, perhaps just checking that the things work at corners of the envelope (sea level being the altitude corner, perhaps with a low speed value added in). Or I suppose he could be planning some minimum weight tests last and needs to get the fuel state down to a particular level.
One thing I'd put my money on, flying out of Warton on company budget, they won't just be playing.
G