There are a number of topics in the forums on how to use motion sensors to capture only the right triggers in the bedroom. It’s always tricky because you spend so much time nearly still. So these might be of interest.
In my own case, I have a motion sensor on the side of the nightstand pointing right at the bed and as I get out of bed I swing a hand over it to trigger it. So nothing else triggers it in the room, including my dog.
I agree pressure mats can be really practical for a lot of people.
Samsung is supposed to have a new sleep sensor coming out sometime this year which is kind of a fancy pressure Mat combined with a sleep monitor that will go underneath the mattress. It’s supposed to work with smartthings, but it’s not available yet.