The exhaust manifold temp is not so surprising given the temp of exhaust gases. Still it is fairly high. To protect surrounding materials - we were talking about crispy connectors and wires recently - Jaguar put a stainless heat shield over them in XJ cars which seems to be missing in your car.
I’m a bit surprised about the higher temperature of the front exhaust manifold compared to the rear. If anything I would have expected it to be cooled better by the fan than the rear exhaust manifold. So you might cross-check plug faces.
The other thing surprising me is the temperature taken at the expansion tank at the left wing - if that is what was measured as “F”. I would have guessed water getting there should have cooled down considerably … but I didn’t look at the place where the water tube leading to the expansion tank is coming from.
Apart from that: just about any exhaust will be red hot with serious driving - just as brake rotors do with serious braking. Yet, they are up to it.
75 XJ6L 4.2 auto (UK spec)