Ok, update. Surf's up in the tank, but it's not going over the edges. My old Tunze 6100 with the failing clip finally broke loose with the action, so I've re-arranged my sand a bit (a lot). Zap straps to the rescue, it's good for another 10 years.
Let's hope this new wave doesn't break anything.
For those with Tunze and Apex controllers, it's pretty easy to get a wave without the box.