Do those baking paper air fryer liners hold the fat in?

[Nabooh]

In things like burgers/sausages?

Or does itjust seep through to the bottom of the airfryer anyways?

In my experience yes they do hold it all. Brilliant for when you cba to clean the fryer. The only thing I found is the ones I bought aren't very deep so anything like chips that get stacked up still make the fryer a bit dirty