I doubt it is fuel pump related. The system runs at a pressure with injectors open for a certain duty cycle to provide fuel that the ECU calculates.
Let's say that the fuel pump switches off for a second, then restarts. The result for that second would be a drop in fuel pressure as residual pressure allows fuel to flow through the open injectors. With the drop in pressure there will be a corresponding reduction in the amount of fuel actually delivered, which would make the mixture a little lean across all cylinders, rather a single misfire on one cylinder.
Of course T7 being what it is, it will then try to adjust idle speed and increase fuelling based on the lambda readings.
Does that make sense ?
The fact that you have one cylinder where the problem is greater would have me looking at swapping plugs and injectors between cylinders, to see if the misfires follow either of those changes. Just an idea.
Injector issues can of course be as a result of problems with the wiring, so even a fuel misfire becomes electrical