On 03/31/2016 11:37 PM, Stefan Monnier wrote:
> (tho, admittedly, currently our story for Elisp-level customization of
> faces is rather poor, so for those I think that Custom is the only
> reasonable option).

Thanks! Faces are one of the thing I *don't* use custom for. AFAIK it does not let you create and manipulate fontsets; I don't think we have any way to specify these properly, in fact. At least, the question at https://emacs.stackexchange.com/questions/17205/how-do-i-set-up-font-fallback-in-a-robust-way didn't get a single answer.