If I recall correctly, a very restricted number of pricier domestic Hi Fi deck minidisc machines [Yamaha ?]
were equipped with S/PDIF outputs
and possibly enabled to circumvent / allow digital transfer of your own original recordings..???
eg Band song demos...

And possibly some pro studio decks.. ???

But I can't remember for certain.

There was a Yamaha ? multitrack minidisc portastudio,
but again I no longer have any idea if or how digital tracks could be transferred...?????

Our band recorded in a studio which was very proud of it's 'marvellous' new all in one minidisc mastering machine.

I was concerned that the master disc would be lossy compressed minidisc format.
But was outvoted by the singer who was paying for the sessions.

Thing is, once he was in possession of the masterdisc
he couldn't or wouldn't understand that it would be near impossible
to make bit for bit digital clone copies....