This is an excellent article! Thanks for writing it up.
p.s. I don’t want to hijack this thread, but I’d like to mention that all three of the problems discussed in this article were already known to me when I wrote the Base64 implementation in my forthcoming Orsetto framework of structured data interchange languages. (Expect an announcement before Monday about its preview release. Also, for the MirageOS people: my implementations are generally not speed demons. I’ve left a lot of room for myself to make performance improvements in the future.)