When I upgrade from 10.12 to 10.13 High Sierra - where do incompatible items go? Does the upgrade from macOS 10.12 Sierra to macOS 10.13 High Sierra remove any extensions, kernel extensions, Applications or settings that are known to be incompatible or disabled?

I looked briefly at /var/log/install.log and see there are over 20,000 lines of things that were logged during the migration and it looks like a lot of things were moved to /Volumes/whatever/Recovered Items but that directory is now deleted and cleaned up. 

Additionally, there appears to be a runtime check of this: Sep 10 16:53:56 MacBook osinstallersetupd[514]: Retrieved package com.apple.pkg.CompatibilityUpdate (http://swcdn.apple.com/content/downloads/47/49/031-75970/fhywgjppj47p6n4udnsqtyszmwfwjt78aj/OSX_10_12_IncompatibleAppList.pkg) package that now has a 404 not found error.

Are there places to look for what was removed from a specific Mac post upgrade if there's not a more comprehensive list of things we can check before an upgrade?
Incompatible items are moved into a folder at the root of the drive when migration or upgrades happen.


https://support.apple.com/en-us/HT201861



  The software is moved to a folder named Incompatible Software, at the top level of your Mac startup disk.