A lot of people are doing this now. Jon Swenson (eR designer) recommended using an FMC in front of the fibre. Which is what the EtherRegen does in reverse order, B > A.
I do this in one of my streamers. Since I do this and fibre I do not care about the crap on the bad side of the eR moat.
Some of the official sound police engineers on A’gon like to say the Swenson is a quake but for me the improvement in sound is real ducky.
BTW - fibre is all I use it it very easy to hear improvements with fibre in my setup. As I said before I have a alot of crap on the bad side of the fibre. The fibre and FMC clean this noise up, so the noise does not get into the DAC. How can I tell? I just replace the fibre for Ethernet and listen.