Outdoor 3 pin socket - need one that closes fully

I've used an outdoor socket for years without issue in all weather. The cover will close mostly when the EV 13A plug is connected. Definitely enough to prevent water ingress. I considered enlarging the hole, but decided long ago it wasn't necessary.

Disclaimer: Mine is also mounted below a larger control box for one of my gates, so it has extra protection from rain. I also have it on its own RCBO since earlier this month.

You could try it and see. I had a similar problem, but solved it by carving the rubber out a bit to allow a better fit.

that rubber is what keeps it water tight

Yeah. It's also at the bottom which will not have rain directly hitting it, plus it would require water to travel upwards in contravention of the law of gravity even if it could get past the tight fitting cable inlet. Mines been there for well over a year and it's dry as a bone.

Some wind that blows upwards specifically towards something 400mm off the ground.

If you're needing ridiculous scenarios to make your case, maybe you don't have one.

1. No idea what you're saying here. "Pick water you"?
2. The IP66 standard requires complete dust and water tightness from strong water jets. You're not getting that from rain, regardless of severity.
3. The cable being higher than the socket, just means water will run down to the lowest point and drip off, it still won't defy gravity and climb up to the socket.
4. And the whole point of the exercise is to allow the cover to close tightly. Taking out some rubber so it closes, is a far better option than leaving it unlatched. It's still going to be tight because the cable is much thicker than a standard power lead.

You've no idea what you're talking about. Have you installed and used an outdoor IP66 socket?

In that case, you should know that what you're saying is nonsense. Granny charging cables are at least twice the diameter of standard power leads and will only fit (extremely tightly) if some or all of the rubber seal is removed. And they have rubber insulation which takes the place of the seal.

That's enough of your nonsense. Ignore list for you.

This one is designed for granny chargers.

https://www.electricalcounter.co.uk/bg-weatherproof-mode-2-electric-vehicle-13a-charger-a-type-dp-rcbo-ip66