@DiogoConstantino @firefoxwebdevs A "live switch" would do the same but has to be activated before to enable the slop.
Seeing that FF activated the slop without having the option to deactivate it (beside in about:config) lets me think the "kill switch" would/will mean opt-out.

@firefoxwebdevs We don't want a "kill switch" aka Opt-Out, we want a "live switch" aka Opt-In!

I think it should be very clear by now that most people don't want slop by default.
What is so complicated to understand that?

Opt-Out == bad
Opt-In == okay
slop as add-on == best option