If you're running Security/AV software on your Mac, it may interfere with updates. (Several threads in Apple's forums on major problems updating to 10.13.4 from some users, as usual.) Of course backup your current boot drive before updating. (And a bootable clone is a plus.)
"eGPUs are supported on MacBook Pro notebooks released in 2016 and later(1), iMac computers introduced in 2017 and later, and iMac Pro. Your Mac must also have macOS High Sierra 10.13.4 installed..."
1. If you're using a 13-inch MacBook Pro from 2016 or later, always plug eGPUs and other high-performance devices into the left-hand ports for maximum data throughput.
Also has notes on app support & link to developer page on coding apps to support eGPUs. (Although Apple only lists support for Thunderbolt 3, for years some pre-Thunderbolt 3 Mac owners have used graphics cards in Thunderbolt cases with modified drivers. Here's an example reader report from 2015 using a Late 2012 MacBook Pro with Thunderbolt 1.)
FYI on Nvidia Web Driver Updates:
Users of Nvidia's web drivers should know that new OS updates (versions or later build numbers after Security Updates) break any currently installed Nvidia web graphics driver. I'd switch to the default Apple driver and reboot before updating, if your card is supported with the default drivers. If not, wait for a Nvidia driver update. (Some non-Mac EFI cards are not supported by default OS X drivers.)
Of course have a current backup (and if possible, a Clone) of your boot drive before any update. (As usual, I'll post download pages for Nvidia updates when spotted.) UPDATE: See Mac Nvidia CUDA and Graphics Driver Updates for downloads of new Nvidia CUDA 387.178 and Web Graphics drivers for macOS High Sierra 10.13.4 and new builds of 10.12.6/10.11.6 (after installing Security Update 2018-002 above).
tvOS 11.3 release notes (Apple TV 4K and 4th Gen)
- Apple TV App: Now available in Brazil and Mexico.
- Siri now understands Portuguese in Brazil.
- On Apple TV (4th generation), you can play videos in their original frame rate.
(That option was already supported on Apple TV 4K. tvOS 11.3 for Apple TV 4K supports Sony TV's Dolby Vision "low latency" profile.)
watchOS 4.3 release notes
This update contains new features, improvements, and bug fixes.
- Control volume and playback on HomePod from your Apple Watch
- Restores ability to control music on iPhone
- Use any orientation for Nightstand charging mode
- Fixes an issue where Siri music commands were not working for some audio devices
- Fixes issue where Activity achievements were incorrectly awarded for some users
- Siri watch face now shows progress towards closing Activity rings and when new songs are added to Apple Music mixes.
FYI: Apple revised their article on Deploying apps in a business environment with iTunes with an updated download of iTunes with built-in App store. Now downloads iTunes v12.6.4 (was 12.6.3). v12.6.4 reportedly allows syncing/backup of iOS 11.3 devices, which v12.6.3 didn't.