Out-of-the-box, when the the PDL356PB2MBTZ‑VW's is used as a Zigbee device and the wall switch is manually operated, it will always physically cut power to the device, e.g. a light bulb. According to PDL support, "There is no capability to convert that action into a command that instructs the bulb itself to turn off while maintaining constant power." 

However, this story is totally different when using Wiser only devices, apparently. PDL support also says "The behaviour where a switch press sends a control command (rather than cutting power) is only achievable within the Wiser ecosystem using compatible Wiser devices and a Wiser Hub configured with automations."

From what I can gather from Google, this ability is called "software disconnect" or "detached mode".

Given PDL only officially support their own ecosystem, it doesn't surprise me they do not give instructions on how to make it work with third-party Zigbee ecosystems. But given the PDL switch is merely a rebranded TuYa device I see no reason why it would not work.

Has anyone got detached mode working with Home Assistant and no Wiser hub?

I am asking because I added an Ikea matter smart bulb, and I'd like to be able to turn it on and off using the wall switch, without cutting the physical power to it.

The Google AI overview did claim "Have a licensed electrician permanently wire the circuit so the smart light/load bypasses the switch mechanism. Wire the switch mechanism to a 240V unswitched Active and Neutral for power only, and connect your smart lights to a constant hot. This means the switch always has power to communicate with your Zigbee network but won't cut power to the lights." I have zero clue if this is rubbish or correct. I don't trust AI overviews, and I'm not an electrician. But if it's true, that could be helpful should an electrician be required.