would innuos mk3 streamer benefit from network filter

Which Innuos Mk3 streamer are you using? Is it the ZenMini Mk3 without the linear power supply unit, the ZenMini Mk3 with LPSU, the Zen Mk3, or the Zenith Mk3? The sound does get better as you move up the chain, and the strategies to improve the sound may vary with each specific unit. For example, adding the LPSU to the basic ZenMini should improve the sound significantly, but the Zen and Zenith already have excellent power supplies.

I have been listening to the Innuos more, sounds better, maybe did need some break-in. Plus it is now in my second system which does have a cheap Forman power conditioner.

My streamers all have a different sound signature, which is a bit of a surprise to me.

So at this point the Innuos Zen mk3 sounds very good, just different than my Lumin and Aurender.  App is pretty good, and works well as Roon Endpoint or Core and Endpoint.

From the replies, I suspect I could benefit from some ethernet filters or audiophile switch.

My Innuos streamer/server is also a Zen Mk3. I use a Network Acoustics Eno filter on the ethernet cable feeding into my Zen. Other NA ethernet filters, such as the Muon Pro, are reported to be even better but they are more expensive than the Eno. I also use an English Electric switch prior to the Eno filter, and a better switch (such as the Innuos PhoenixNet) might improve the sound quality even further in my streaming system. I have been very pleased with the increased naturalness obtained by using an Innuos PhoenixUSB between the USB output on the Zen and the USB input on my DAC. 

+1 on Network Acoustics Eno filter. It really removed any remaining digital artifacts from the signal. Another tweak that resulted in a nice improvement was replacing the stock fuse with Synergistic Research Purple fuse. 

+2 on the Network Acoustics ENO. I had a Phoenix USB but sold it. The ENO made a much bigger improvement and it was imediate.