Add .staging.wpengine.com to allowed dev sites
Also: GoDaddy, Flywheel, SiteGround, etc...
Kevin Roberts commented
Please also include .dev.cc which is now the default TLD for people like me, and many others, who use DesktopServer from ServerPress.com for local development.
ServerPress owns the .dev.cc TLD and has released it for use by the community so that any local development environment can use it (see https://wptavern.com/desktopserver-3-8-4-includes-a-gift-to-the-community).