Well, USB to Toslink just requires a converter, not a DAC, since they’re both digital. It’s just that the functionality is a little tricky to find on its own. The Mutec MC-3 is all digital and often recommended for this purpose, overkill as it may be.
https://www.mutec-net.com/product_mc-3-plus-usb.php
Edit: I don’t recall seeing this the last time I looked. I think I might just pick one up...
https://www.rcblogic.co.uk/product/cyp-usb-digital-audio-converter-192khz24-bit
https://www.mutec-net.com/product_mc-3-plus-usb.php
Edit: I don’t recall seeing this the last time I looked. I think I might just pick one up...
https://www.rcblogic.co.uk/product/cyp-usb-digital-audio-converter-192khz24-bit