> A consumer can download Xcode, build their own app, install the app on their own device, and use Apple API, all for free. What they can't do is distribute that app to other consumers.

I was referring to the distribution of the licensed technologies by Apple to the hardware purchasers. Returning to your own interpretation though, the hypothetical community SDK wouldn't contain proprietary code, so the distribution aspect is solved there. It's the same principle by which homebrew game console scenes work, or how you can build Windows software on Linux without touching any Microsoft code.

> This doesn't answer my question. I asked which fee needed to be waived. There is no fee to get Xcode, so there's nothing to be waived by opting out.

The waiver scenario is meant in the context of Apple using the 5% and $99 fees as payment for the maintenance/R&D of the official dev experience. The fees would be waived because the dev isn't making any use of those tools in a hypothetical FOSS SDK.