Can the Motion Sensor + Alexa do this?

I’m new to Z-Wave and SmartThings so I have a few questions.

Initially, I’ve set my entire home up with either occupancy/vacancy switches or timed switches. For example, linen closets and certain bathroom (fans) are set up on timed switches (for obvious reasons). My kitchen, main bathroom, guest bathroom, powder room (no shower) and garage are on occupancy sensors.

This set up has mostly worked very well but I’m considering swapping out a few of the switches for Wifi ones and then getting a few motion sensors. The reason for this is, as an example, my garage light switch is beside a closet (that I don’t want to have to move) and isn’t triggered until someone gets out of the vehicle all the way after it’s in there. I would rather the light come on as soon as the overhead garage door opens and turns off when there’s no one in ther. Another example, my kitchen is open and the switch is ironic, my fridge is within LoS so if someone is standing by the stove and doesn’t move around for a while, it turns off. But if someone in the Family stands up or walks by, the switch comes on (which means it’s on more than it should be). I can remedy all of this with strategically placed motion sensor.

My fix would be this. Purchase wifi sensors to replace these switches. Purchase some z-wave motion sensors. Use Alexa to (let’s say, for my kitchen) “when Kitchen Motion is triggered” -> “control Kitchen Switch -> set to on”. I know this can be done. What I don’t know is if there’s a way to turn it off and if I can set a delay. I wanted to check here before I invest in a motion sensor and wifi switch. What I want to do is, (back to kitchen) “when Kitchen Motion is 'no motion detected for so and so” -> “control Kitchen Switch -> set to off”. Does anyone do this or know if this can be done? The idea is to turn the light on when someone is detected and turn it off when no motion has been detected for a minute or 2. I know the motion sensor technically opens and closes like a door contact, it automatically closes after I think 40s (for smartthings motion) after not detecting motion. I’d like a slight 20s delay on top of that, basically. The main differnce between this and my motion sensing light switch is that I’ll be able to place the motion sensor where it will detect someone in the kitchen, no matter where they are BUT not while they’re in the Family or Dining area.

Thanks!