Pretty bizarre if people do this. I’ve never heard it to mean anything but linoleum.

But a lot of people in the US use the word “turf” to specify not turf (i.e. artificial turf), so there’s no reason for words to mean things.

What? One of linoleum’s benefits is not off gassing and not being made from fossil fuels. Are you thinking of vinyl?

why is there no switch to enable type checking at runtime?

Have you got problems this would solve? I’ve done a lot of type annotated Python at scale and I can’t think of an example.

Edit: given nobody in their right mind allows code that’s not checker clean.