As promised, the iOS 17.5 beta includes support for sideloading apps directly from authorized developer websites in the European Union.
Apple App Store
When Apple first released its plans for complying with the EU's Digital Markets Act, it only intended to allow sideloading via authorized alternative app marketplaces. Regulators disagreed with this implementation and pressured Apple to add support for website downloads as well, and it promised to by a spring update.
Code references to Web Distribution discovered by MacRumors suggest iOS 17.5 will enable sideloading from websites. It's not possible to sideload any app from any website, as Apple still requires stringent security checks and authorization.
Developers must sign up for the new EU business terms that allow them to create third-party app marketplaces. To do that, they must have been in the Developer Program for two years or more and have an app with more than a million first installs annually.
Apple didn't directly mention the alternative requirement for app marketplaces as a possible option for developers, but it could also be allowed for Web Distribution. The alternative requires a standby letter of credit of one million Euros and two years in the Developer Program.
The first iOS 17.5 beta released on Tuesday, April 2 with minimal user-facing updates like changes to the Podcasts app widget. The public release likely won't arrive until sometime in late April or early May.