Playing Devil's Advocate first. Yes it would be better for Luca in the immediate term to not have a long journey, possibly an overnight stay in a strange room (even though you are there, he can't see and won't know the layout.) I agree that on the way home he'll be pretty much out of it, even so it would be nicer for him to be at home in a familiar place, with you able to cuddle and soothe him as he comes around.
But of
course you must consider saving £650. Perhaps one of the reasons the Bournemouth vet is so much cheaper is that this
is his or her specialty, and therefore could be not only cheaper but better.
They must not know you very well on your blind dogs' forum, KC, if they don't know that you would always make the dog's own interests paramount.
You know your dog, so if you are comfortable that he can withstand the journeys, then none of us is going to gainsay you.
So the only other reason I can come up with to think twice about the long distance vet is aftercare. It's obviously preferable to be able to take the dog back to the vet who performed the operation. But this is enucleation, there shouldn't really be any complex aftercare needs. Many years ago I had a dog needed an eye removed and, on my vet's recommendation, I took him to a vet hospital a ways away to get it done. I can't remember going back there to get the stitches out, I am sure all the aftercare was straightforward and readily accomplished by my local vet.
You do what you feel is best, KC, and if the other forum members want to be idiots, you know you will get a lot of support - and admiration for all that you do for these waifs, too - here.