As an occasional Gatwick approach controller, but not at work during this windy spell, I'd only comment that I'd hope we'd accomodate any speed that is different from the norm (160 to 4) when it is requested.
I'd only ask that the the requirement is stated on the downwid leg at the latest, if it's made when you're already on the ILS the chances are that the a/c behind you may already be on a closing heading or established and as such it might be a bit tricky to then increase the spacing if required.
During LVPs the normal spacing at EGKK would be 6nm if no departure in the gap, or 10-12nm if there is a departure. That works for LVPs but it might be a bit OTT in other poor weather scenarios.
WF.