Pairing PP with different HRM

[ktula]

This is the scenario. In the profile #1 on PP, it is paired with a Wahoo speed/cadence sensor and a Wahoo HRM. If I want to use a different HRM for ride, do I need to put PP in pairing mode (pressing and holding the button for 4 seconds) for it to recognize the new HRM? Or is simply turning on the new HRM and waking up the Wahoo speed/cadence sensor prior to turning on PP sufficient?