MBP 15" 2017 (Radeon 560) + eGPU Radeon 590 + Bootcamp

Hi there,

I come to you absolutely desperate after a whole night of trying literal dozens of re-installs of BootCampDrivers versions and I haven't made any progress.
I will preface this by saying that this is an issue regarding specifically the combination of an MBP, an eGPU and drivers ; the MBP and drivers alone seem to work fine whichever I pick.

Here is a quick description of my setup so far:

• The computer is an MBP 15" from 2017 (internal GPU is a Radeon 560)
• The eGPU is a Sonnet Breakaway with a Radeon RX 590
• I have an external screen plugged to the eGPU
• I use BootCamp with a Windows 10 install (v1809)
• For the past year and a half I've been successfully using the BootCampDriver Red from November 2019 (edition A)

So far so good, the driver was extra-outdated but it worked as long as I booted windows with the eGPU plugged-in.
Except, it's getting too outdated, and I'm getting either denied or I get crashes in apps from the past few months.

In order to attempt to update this driver, I tested the following:

• October 2021 Red (without prior DDU, then with DDU, without eGPU during install, then with eGPU during install)
• April 2021 Red (with DDU, without eGPU during install, then with eGPU during install)
• November 2020 Red (with DDU, without eGPU during install, then with eGPU during install)
• May 2020 Red (with DDU, without eGPU during install, then with eGPU during install)
• November 2019 Red (with DDU, without eGPU during install) then upgrade to May 2020 without DDU

All of these gave me variations on the theme of random BSODs, and at the best of times an unrecognized eGPU.
IIRC November 2020 did notice both the Radeon 560 AND the Radeon RX 590 at install time when it was plugged, but then it ended up not being recognized post-install.

What should I do to get (more) up to date drivers?
Is it at all possible with my setup?
Should I challenge my Windows version?

Thank you all in advance and keep up the good work.