To help with language learning I tried Anki, didn't like the UX and ended up writing my own SRS, from scratch.

One thing that becomes very obvious very quickly is that all cards derived from the same piece of information should be treated as a group. The last thing you'd want is to see "a cow / ?" quickly followed by "una mucca / ?". This is just pointless.

So while I appreciate the in-depth write-up by the author, I must say that its main insight - that the scheduling needs to account for the inter-card dependencies - lies right there on the surface. The fact that Anki doesn't support this doesn't make it any less obvious.