Update!
So, I did a few of research. I compared some different WCNSS_qcom_cfg.ini files.
I checked the
taimen (Pixel 2XL) android-8.1.0_r60 tagged
taimen android-9.0.0_r33 tagged
crosshatch (Pixel 3XL) android-9.0.0_r33 tagged
stock Codename Phoenix Rom
and stock OOS 9.0.3
files.
Both Pixel's Pie files lead to a non-working Wifi (it can't be turned on). The other files work. So I decided to perform a merge for the new update, as the stock taimen android-8.1.0_r60 tagged file works on OOS and the stock OOS file works on AOSP. So what I did is to take the AOSP Oreo file as base and compared it to the stock OOS files - I included missing lines and additionally changed some values here and there as on previous releases.
So here we go, here you can get the v15 update: Pixel2_WiFi_MOD_v15.zip
or attached here
or attached in the OP, as always. Enjoy!