I speak from experience when I say, the tiny section from the rear cylinder head is an absolute abortion, hence why Honda quickly made two sections into one, when the exhaust was redesigned on the SP2.
The rear cylinder on mine always seems to run hotter and whenever one of the rear gaskets blow, the centre part of the exhaust always rattles up and down and thus destroys the other gasket just for good measure.The last time I took the rear short pipe off, the gaps between the rear shorty pipe and the main collector was so big, I actually took the centre piece out, without needing to undo the clamps on the other sections
Welding the shorty pipe to the next one, means that joint will never leak again and eliminates a big risk and the difficulty faced trying to undo the nuts on the rear exhaust studs, one of which is behind the shock and an absolute slag to undo if you have an aftermarket shock on the bike as you cant get a ratchet bar of any length on at the angle the nut sits at.