First of all, big thanks to @tluck for great work.
I've recently switched from T520 with Intel card only, which have been working perfectly on High Sierra, to W520 with nvidia card onboard. It is working fine, although I have some issues:
No image on external display on Intel card using display port. I've read that this is supported only on nvidia card, which leads to another issue.
Nvidia card is not working on thinkpad's LCD, I've installed latest web driver 'WebDriver-3126.96.36.199.15.121.pkg' http://www.nvidia.com/download/driverResults.aspx/126157/en-us andswitched to MacBook Pro 10,1 profile with no luck.
Two USB 3.0 ports - after adding mXHCD.kext from @jenyunhuang, it works but it is terribly slow. Does someone else experienced this issue?
Would somebody be willing to share theirs W520 configuration (config.plist, DSDT, kexts, etc...) or maybe give some advice on the above issues?