I cannot comment on what other measures can be used to improve your particular environment but I hope my experience with a GISO will help you make a decision.

I placed a GISO between my switch and my ID41 and the improvement was immediately noticeable.

The noise floor dropped and the sound became clearer. I was so impressed that I took my GISO to my dealer who tried it in the equivalent position on some Non Meridian gear and the result was similar.

As the ID41 is supposed to be more noise resistant than the ID40, the effect of the GISO should be more pronounced as all the GISO can do is remove noise on the Ethernet.

I know that the bits are bits people will come out and say it should make no difference but in my experience it just does!

I have noticed quite a difference in playing Tidal on the ID41 using a MD600 and my PC using Roon.
The difference is similar between those combinations and Soolooos with a GISO and without.

861v8+ID41 Revelation One filter, HD621, Musical Fidelity M8 700 mono blocks, Focal Scala (x2), Focal Mini Utopia (x3), Velodyne DD18, Oppo BD105, Roon NUC, 218, Radiance 2021, JVC X9000