(4) is better but it would have to be every single time, because (2) is impossible to define.
It's like spam: a precise closed-form analytical definition is impossible, but spam filters do work.
Browser vendors could hypothetically start adding specific types of exceptions to make certain types of the 'hidden box' trick not work, but that would ultimately mean those website developers simply switch to whatever method works. The problem isn't solved, it's just re-coded.
TLDR: There is NO SOLUTION, because there is NO PROBLEM. The feature works as intended, as written in the spec.
(I say this as a matter of how you express such things, not about this particular case. I agree with you in considering there to be no bug here, but rather that this is a serious feature that shouldn’t be messed with—and pretty fundamentally can’t without unravelling substantial foundations of the web platform.)