You raised questions worth pondering. If you recall our previous conversations, I always advocated for less is more. Having said that, each system is unique and then there are user preferences. I honestly believe adding or mixing more than one of these noise canceling devices doesn’t always yield to improvements that are monumental or worth pursuing at the added expense of complexities or chaos.
In regards to effectiveness of devices like MI-300 and iSO-CAT7, I think their existence in your system is going to largely dependent on your components downstream. I have tried a reputable net isolator similar to MI-300 in the past and couldn’t justify its existence in my system. I will soon be trying the iSO-CAT7 filter with upcoming trial of fully tricked out SOtM switch. I haven’t felt the need (until very recently) to mess with my network since purchasing M12 switch, 18 months ago. A simple switch that checks all the boxes between my router and Streamer/DAC.
And lastly, a recent communication with Rich at Networks Acoustics confirms, Muon Pro operating at 1Gb/s sounds better than the standard 100Mb/s version.