EULA Text explicitly links the fee to the Binaries, but the website FAQ implies a much wider scope.

[JackCoplandGranta]

The EULA Text is pretty clear that the fee agreement is linked to consuming binaries:

Project agrees to provide User with the Binary Release in exchange for the Fees outlined in Section 2...

By accessing or using the Binary Release, User agrees to be bound by the terms of this Agreement...

This Agreement applies only to the Binary Release...

I was under the impression from that text that a party that built their own binaries from source would not be covered. However the "What if I don’t want to pay the Maintenance Fee?" section in the website FAQ (https://opensourcemaintenancefee.org/consumers/faq/) mentions a far wider scope of activities that imply accepting the EULA:

Do not open issues. Do not ask questions. Do not download releases. Do not reference packages via a package manager. Do not use anything other than the source code released under the Open Source license.
Also, if you choose to not pay the Maintenance Fee, but find yourself returning to check on the status of issues or review answers to questions others ask, you are still using the project and need to pay the Maintenance Fee.

If indeed, for example, asking questions on the Github repo implies accepting the fee agreement should that not be made explicit in the EULA text?

[robmen]

You are correct. The EULA is solely focused on the terms for downloading/installing the binaries.

Could the EULA include additional terms laying out all of the other restricted interactions with a Project? I suppose. But, doing so would complicate the EULA, which is very carefully crafted to work with Projects' Open Source Software LICENSEs.

Instead, it's easier to include all of the expectations in the Project's README and use mechanisms closer to the restricted feature (such as the EULA or GitHub issue template) to remind/enforce consumers if an Open Source Maintenance Fee is required. This design also ensures that the Maintenance Fee requirement is displayed/enforced even if the individual in question (aka: the person opening an issue) is not the person who accepted the EULA for their organization.

You can see this at work in the WiX Toolset. The Project's README (here and here) introduces the Maintenance Fee. The EULA (here) enforces it for binaries. Finally, the issue template (here) guides consumers down the right path.

PS: I received feedback from some maintainers that they may want to allow consumers to participate in restricted facets of their Project (like Discussion items) without paying the fee. It is on my TODO list to update that FAQ entry to soften it a bit and indicate "Project choice" on Maintenance Fee enforcement.

In the end, the guidance on the site is to read the Project's README: Again, always check the project’s README file to verify if and how to pay the Maintenance Fee.