Don't Install If You Jailbreak & Own a Newer iPhone
If your device is jailbroken or you think you might want to jailbreak your device, you might want to avoid iOS 13.4 for now.
There is a jailbreak (dubbed checkra1n) that's available for iPhone 5s-iPhone X running iOS 12.3-iOS 13.3.1. However, the jailbreak tool is currently in beta testing. It's also unclear if it works with iOS 13.4.
Jailbreak developers have also released a working jailbreak tool for iOS 12.4, but it doesn't work with newer iPhone models like the iPhone 11 series or the company's 2018 iPhones.
If you want to jailbreak an iPhone XR, iPhone XS, or iPhone XS Max, you need to be on an older version of iOS 12. Unfortunately, there's no way to downgrade to iOS 12.