I have found a potential fix for spoilers, especially ones that are nested or experience the duplicating bug.
The downside to this is that it would require us to change to a different spoiler module, this would break any spoilers on the forum already and would need to be converted to the new syntax to work correctly.
We don't have control over these modules, so before you pick no, remember that if you decide to keep the current one that's "broken", you'll have to live with the faults that come with it (I will be ignoring any moaning about it) and it was last updated by the developer 12 months ago...
What do you want to do?
Example syntax here:
Styling will be sorted, if the module gets approved.