Oops, sorry about that...
Wrt 2/2, my original intent was that these would eventually be exposed as API, and in that case I think byte size is a bit more intuitive to deal with than vec4 size. In that case I intended to fix spirv to treat the size as a byte size, but forgot to do that (and of course the tests didn't catch it, since it just resulted in declaring larger buffers than we actually access).