I have not put forth much effort to really test it, but I have never heard any difference in my system when it comes to audible changes from things in my system transferring the digital signal. I've heard differences from tubes, power cords, interconnects for reference. It's been a while since I did anything with optical/toslink in my system and currently use SPDIF. I recently upgraded from a cable from Blue Jeans Cable to a Cinnamon from Audioquest and didn't hear any difference.
Toslink does have limited bandwidth so cannot transfer high resolution files. I tried a Schiit DAC and had to use SPDIF to get the files to transfer. I don't normally use high resolution files, so this was a bit of a surprise to me.
I'm not saying that digital connections cannot make a difference. I've just not heard it in my system and if I'm honest I'm happy to avoid that rabbit hole.