That's interesting. You mean essentially a transpiler either from cron->schyntax or schyntax->cron? The former seems more doable, since I think there are more schedules schyntax can represent which cron can't, though a subset could work in either direction. I've also considered a native utility https://github.com/schyntax/schyntax/issues/2 as an outright replacement for cron, which could benefit from a transpiler.
If there is interest in this, I'd definitely be open to discussing it more on github.