How long is a piece of string?
Generally I find the ebb here fishes poorly but that’s not the same for every mark, they all vary.
Quite often two hours of ebb then it dies off seems to be the norm here, but we have a big tidal range. There are a couple of marks that do produce on the back tide.
Does the tide move much in Sussex? On my local surf beaches you can’t really fish the main ebb as you’re chasing it down so much - literally by the time you’ve baited and cast one rod, then done the other, the first one is practically dry.
Not to mention how quickly you have to chase after it, it just becomes impractical.
But if Sussex is like chesil where it just about manages to move three metres in three hours, that aspect won’t be an issue.
As already said, try different tide states and see if it works.