we can add a custom recovery to the rom. it's actually really really easy to do. we just don't because it protects users from bricking phones. to put it simple, in the leaked kernels, there's apparently a bug, which isn't cm exclusive. when formatting a partition, it can fail on a random occasion and mess up your partition table. that essentially hard bricks your phone. this is the reason we're not including a custom recovery in the kernels just yet. once we get kernel sources, our developers (or anyone else into kernel developing) can try and pinpoint that bug, patch and fix it.