Do the effects of abilities like pressure and stealth o-power stack?

Question

In other words, do abilities that decrease the encounter rate state with the decreased encounter rate of Stealth O-Power, or any other effect that limits but doesn't completely stop encounters with wild Pokemon?

Answer 1

Yes,they do stack because they are not one of the same thing but two different things that reduce the encounter rate of wild Pokemon.It's like using Hatching O power and having a Flame Body/Magma Armor Pokemon.

List of abilities that reduce encounter rate.

Hope I helped!