Okay, after looking at the two files that both mods make changes to...
they both change the same five values in Sensors.cfg, but the new values are similar:
(in No Cont Ship Spotted)
Visual range factor=1.4 ;[>=0]
Visual fog factor=1.0 ;[>=0]
Visual light factor=1.6 ;[>=0]
Visual aspect=0.4; ;[>=0]
Visual sensor height factor=0.5 ;[>=0]
(in MEP Sensors for GWX)
Visual range factor=1.4 ;[>=0]
Visual fog factor=0.9 ;[>=0]
Visual light factor=1.6 ;[>=0]
Visual aspect=0.7 ;[>=0]
Visual sensor height factor=0.5 ;[>=0]
The biggest difference is in Visual aspect, the only other difference is in Visual fog factor.
I don't know what these values do, lol, so I don't know how significant those differences are when it comes to avoiding the constant "ship spotted" alerts for the same ship.
According to the readmes for both mods, the only changes made to Sensors.dat are to the Visual sensors:
(in No Cont Ship Spotted)
PreciseRange=15500
MaxSensorHeight=20000
Surface=50
SweepPeriod=5
SweepArc=0
ProbInsideArc=0
(in MEP)
preciserange=19500
maxrange=20000
minheight=0
maxheight=15000
minsensorheight=0
maxsensorheight=20000
surface=50
rpmdetlevel=0
sweepperiod=5
sweeparc=0
probinsidearc=0
revolving=false
skipsweep=true
At first glance it looks to me as though it's possible that Makman94 incorporated the values for No Continuous Ship Spotted into his Sensors.dat and Sensors.cfg files, with the changes necessary to increase the crew's visual range to work with a 20km environment. Since I don't know exactly what those values in Sensors.cfg do, I can't say for sure.
But it may just be the issue of not having a high enough value in Sensors.dat for preciserange and maximumrange of the visual sensors.
What I would try first is just using the MEP Sensor pack without enabling the Ship Spotted mod at all, and see what happens. That's how I've been playing, but TBH I haven't spent enough time outside of the harbor except in very short test runs, and you know in the harbor it's "Schiff gesichtet" nonstop and not because the WO keeps seeing the same ship for the "first" time over and over again... it's because there are just that many ships around, period.
Anyway - if just the MEP Sensor pack doesn't sort the issue all on its own, then I'd think the next step would be tweaking one or both of those values in Sensors.cfg that differ between the two mods. Maybe someone can tell us what they do and that will shed more light on the issue.