>I have learned that the biggest bottleneck ... is just entering cards into the system.

Couldn't agree more. I think I would take this opinion and go even further -- we shouldn't be making cards fully by hand much, if at all, anymore. AI-assisted card creation is to me clearly the future, and already AIs are good enough for this to work well.

This looks really cool. I thought in the past about implementing something like this myself.

I have use anki, and briefly mochi.

Having plain text cards that are simple to edit and manage with basic linux tools is really important.

I have used the genanki python library in the past to generate cards, but it's not great.

Going to give this a go.