SEZ rwy 13 requires careful planning, not only in how the approach to a visual conclusion will be flown, but the fact that as a destination it requires " island reserve fuel". In other words, if the weather is marginal, the alternate is at least 2 hours away. If the weather is indeed marginal in terms of cloudbase and surface wind, then it is a difficult decision to make, whether or not to 'press on' or divert from a reasonable altitude. If the approach is to be attempted in such conditions, then it needs precise flying and I would suggest the possibilty that GPWS warnings are triggered when 'going visual' and inadvertently increasing the RoD to slot into the rather dim PAPIS. At that time, the aircraft is pointing more at the cliff immediately south of the runway.