We've seen what the limit of a Duel "refurbishment" is. No chance of any more than that because your ability to capitalise on a refurb of a ride few people outside enthusiasts care about is limited.
Haunted House rebuild is probably more marketable but was expensive in 1992. It's a sadness that we have so little confidence in the park that we would prefer the ride as-built 30 years ago rather than a modern day imagining of something similar, but there we are.
What I'd like is something using the existing frontage and ride system but starting again internally. Whether that's called Haunted House, Duel or something else, I don't care.
What I actually think will happen? Pin badge.
It's not that we prefer old stuff over new stuff for nostalgic reasons, it's that, to put it bluntly, most modern day attractions have no emotion or charm to them, unlike the 80s and 90s which had, with the only one probably still pulling it off well is Nemesis and The Runaway Mine Train. I just believe Duel is capable of retaining that feeling and charm once again as the HH. We've got a whole new generation that want to experience these old attractions for the first time, but the previous generation that already did it dont want to because, like I said, they've already done them attractions, so it's a 50/50 argument really. One side wants old, the other wants new.
Like I said in one of my old comments. There should absolutely be new stuff in every theme park to keep it up to date and unique. But that being said, there should be a balance of new and old stuff. Take Knoebels for example, with their vintage attractions and new ones coexisting, and their Huanted Mansion still being considered one of the best Ghost Trains in the world, and over 50 years old with little change technology wise, yet people still love it. I believe that Duel can become the Knoebels HM of the UK as the HH once again.
Should Duel have some technology advances? YES, absolutely, take the Giant spider for example, all it needs is some extra fluid movement and then it's up to date. Just replicate the old prop mechanisms with a more reliable system and structure. This goes to a few as well, such as the last screaming head, it's mechanic is incredibly loud now. And the Crazy man in the garden, he seems to slowly turn at you rather than jumping out at you. And of course how can we forget about the *COUGH* Tr- *COUGH* -ommel. All it needs is better accessibility for maintenance.