I only use the pulse mode, and trigger a scene when the pulse on is received. I ignore the sensor's off command.
I don't have this sensor, but I thought in pulse mode the 'no-motion' delay is almost instant, just a few seconds maybe. That seems fine for 'one-shot' applications, like a hallway, to turn the lights on for a minute or so. But to keep the lights on in a room, like living room or office space, I think it would be generating a lot of needless On/Off commands, which drains the batteries, takes airtime, and keeps Vera busy.
All depends on how much motion you're actually generating, but I think you're relying on the sensor not seeing any motion for a brief period at least once within the 'after xx min turn off' interval.