This is mostly just inheriting the weird decision making US side - navy and airforce using different refueling standards rather than some UK screwup.

Not ideal but seems like a reasonable compromise to me given that any scenario where UK is nuking anyone will presumably have European mainland buy in. i.e. could refuel there on the way to where you're going.

In any case seems unlikely that the UK would ever deploy nukes far away. UK is a regional power and has nuclear missile subs anyway for further out if needed.