Two Toslinks but only one BNC and one USB in. That’s a pity . I always thought BNC 75 Ohm was the dig to go and stick to. 🤔
I suspect it’s not so much what’s optimal for performance but what’s useful. Arguably TOSLink offers better sisolation as well as being more universal on things like TVs and MediaBoxes which people are most likely to attach - convenience devices rather than additional high quality sources.
Adding a CD transport is the probable exception where a BNC is worthwhile.