I may have jumped the gun on versioning. Do we know how AMO updates work? Do we want to support a separate versioning mechanism in case AMO updates don't meet our needs, or for our own dev cycle?

Assuming we want to keep it -- now that we have a map and a version, I think it is slightly less verbose and more consistent with the rest of the modules to do

exports.map = blushlist;
exports.version = <version>

I'm of two minds whether or not the version should be a straight int or explicitly rely on the contents of the file. Straight int is easier to understand, but requires remembering a manual update. Relying on the contents (e.g., computing the hash in code on the map) is kind of nice because you don't have to remember to update the version, the code will just do it for you. The way you have it now is kind of the worst of both worlds, because you have to remember to update and it's hard to inspect versioning bugs.