As for 'no matter what size?' BALONELY. This is the kind of thing that makes my mother question the safety of my 15lb dog in a house with 1000 gram snakes. A 4-5 week old kitten MIGHT be in some kind of danger from a BP, but a BP taking on a 3-4-5lb cat? I just can't see it.
LOL, if you've never had a snake attempt to constrict and swallow a prey item that was much much too big for it, then you haven't been keeping snakes long enough.