I perused the sir-trevor JS yesterday. They seem to have a fairly reasonable default toData/loadData impl (https://github.com/madebymany/sir-trevor-js/blob/master/src/block.js#L153). I assume we can't use it because it doesn't work with checkboxes (in which case, PR time?)?

It'd also have the benefit of getting us markdown text entry, which might be nice sometimes.