Was your audio and graphics working after sorting out your kexts and before applying the update?
Where is it failing now? Do you have a fragmented "macOS Install Data" folder on the root of your drive? Delete that and try launching the update again.
Also I want to mention. After applying the update it booted fine and I posted about my success but subsequent boots would crash with a forbidden screen. I don't really understand it but I gave up and left my machine turned off for about 10-15 minutes. When I booted it back up its worked fine ever since.
That's odd about your boot; I can't offer an explanation. But yes, graphics and audio are working fine on 10.13.2 for me. After thinking about it and in an effort to get back to 10.13.3, I recounted some steps from before:
- I disabled the realtek kexts in the kexts/10.13 and kexts/other folder
- Riding the graphics hunch, I injected Intel with ig-platform-id 0x19120000 in "macOS Install from Macintosh"
- Booted into "macOS Install from Machintosh"
Doing this showed the grey installation screen with white macOS install box. It restarted and the installation seemed to complete on "macOS from Machintosh" (the install option was gone). It took about 5-10 minutes. It's running 10.13.3 (17D47) but with no audio. Also if Finder is active and I hit CMD + any letter w/o an action associated with it, the screen flashes white. This didn't used to happen on 10.13.2.
When I claimed success a few days ago, I got this far but without any of the prolonged installation screens I noticed this time. I'm not sure why. Last time I tried reinstalling cloverALC and that's when the boot locked up. Now I'm at a loss of what to do. Fortunately, my working clone of 10.13.2 has saved my system through this!