Though, as with other secret mania type modes, the value doesn't seem to be worth it.
Tryhard time: I'd be curious if you could exploit this on its self a few times to get things a bit more tasty such as:
Force up/down target bank down.
Have basement and roof the only remaining floors. (or maybe basement and floors 4+, or Roof and floors 2-)
Activate secret on floor 3 and collect.
Change floor and reactive on floor 3 and collect.
Repeat a few times.
Cash in on a multiball with a few running at once.
The big question is do they stack, and does the timer reset, or even better, can you increase it past 20 secs.
Then, ultra tryhard would be all that stacked with both basement and roof. Meltdown