Not all are understandable, I really thing Duel should be open. It would be easy to hold guests outside to lessen the number in the small indoor section of queue. I don't think cleaning is a big issue either, just use sanitiser or wash your hands after going on the ride, touching the gun is no different to touching the trolley or basket at the supermarket or the restraint on the rollercoasters.
At the moment keeping Hex closed feels like it makes sense as its harder to judge distance between you and other groups in the dark, but with mask enforcement that should be OK I guess if they really wanted to open it.
The kids shows such as Cookie Monster Hotel should be able to run if its worth performing to small more spaced out groups. But Justins house has too much running about and kids can't be trusted not to get too close etc.