USB isolators - any experience?

Hi everyone,
recently I've stumbled upon "usb isolator" - a small chip, which galvanically separates USB bus from latptop/pc from peripherals - if I understood correctly, the isolator contains pair of coils on each USB wire, and the signals are transmitted via induction.
As far as I know, "mainstream"/intended usage is mostly for two use cases:
- audio enhancement - by reducing noise coming towards your audio setup via USB hub
- HW protection for DIY electronics

There are mutliple models with various prices, starting on 20$ and ranging up to few hundred $. The more expensive ones sometimes allow/require connecting custom power source.

I hoped this could make low/no emf computer mouse/keyboard out of ordinary USB accessories, so I bought one from the cheaper range: ADUM4160 USB 2.0 isolator.

This one has nice switch between 1.5 Mbps and 12 Mbps. I had limited success with it:
 - on all USB devices I tried, switching to 1.5 Mbps reduced RF EMF (sometimes to near-zero level), BUT unfortunately those peripherals did not work anymore (typing on keyboard produced no keystrokes in laptop, moving mouse did not move cursor). In terms of lowering EMFs, you could achieve the same result with scissors
- on some USB devices I tried, using 12 Mbps mode reduced RF EMF to about half/third of original levels (e. g. from avg/peak 0.050 / 0.080 mW/m^2 to 0.015/0.030 mW/m^2). On other USB devices, using the isolator in 12 Mbps did not have any effect at all on RF EMF levels.

(Specifically for PS/2 keyboard connected via USB->PS/2 reduction I got to about half of RF EMF. Please note that I've always connected the isolator as close to mouse/keyboard as possible - e. g. without having any USB hubs between the isolator and mouse/keyboard.)

Does anyone have good/better experience with specific types of USB isolators and/or USB peripherals?

https://www.amazon.com/usb-isolator/s?k=usb+isolator
https://www.analog.com/en/products/adum4160.html

I've tried various USB "gadgets" over the years, sometimes they seem to even make the noise problems worse, not better.

My ultimate (current) solution goes like this:

 - PC
 - USB hub (Star Tech, try it with both the external power adapter plugged in or not plugged in)
 - USB to PS/2 adapter (Belkin)
 - PS/2 keyboard and mouse

I think a good hub can reduce the noise that you might otherwise get from the PC. And PS/2 can reduce the noise you might otherwise get from USB. And a good USB to PS/2 adapter helps as well. It all adds up.

Also I'm sure the specific keyboard and mouse matter as well.  I'm using 20+ year old IBM keyboard and a 25+ year old Microsoft roller ball mouse.

Thanks Marc :) Out of curiosity - did you measure EMF levels of your setup? I am wondering what's the lowest reasonably acheivable level for keyboard/mouse with such setup.

The numbers I posted in my first post are something like maximum measured value when putting Trifield TF2 as close as possible to the mouse, trying various locations/rotations.

Well it's hard to say, because there is an ambient RF reading in the room, which is about the same as what it is at the mouse.  So in theory, the mouse could be putting out nothing, and all I'm reading is ambient. But at the top of the mouse, measured with a Cornet ED88Tplus meter, it reads around 0.010 mW/m2. Top of the keyboard is 0.006 to 0.008 mW/m2.

Thanks, that sounds like I could still reduce the EMF levels a bit. Getting a roller-ball PS/2 mouse seems like the next logical step.