Who would’ve thought? This isn’t going to fly with the EU.
Article 5.3 of the Digital Markets Act (DMA): “The gatekeeper shall not prevent business users from offering the same products or services to end users through third-party online intermediation services or through their own direct online sales channel at prices or conditions that are different from those offered through the online intermediation services of the gatekeeper.”
An example of this in practice is Firefox addons. You need to get your extension signed for people to install it, but you can distribute it however. Mozilla of course doesn’t charge for signing though. It’s just to give them the ability to ban an extension found to be malicious.