Here's the kicker: the compiler that produced this working program is written entirely in Epoch.
Yes, the test program is extremely minimalistic, but it passed.
Self-hosting completion is now just a matter of getting the parser to understand the entire language grammar, and finishing out the last bits of semantic analysis/type system enforcement that still need to be done.
Which is not to say it's a small workload; to be sure, I'm still optimistically gunning for end-of-year to get it done. But it's now a visible target instead of a nebulous future possibility.