wp [theme|plugin] install supports a --version flag. update, however, has odd behavior for this param: according to the docs, any value for 'version' will force the latest version of the resource to be installed, but the code makes it look like only the value of 'dev' is accepted.

It'd be useful for me to specify a version for upgrades. I can look into patching this, but wanted first to ask whether there was a principled reason why update --version acts the way it does.