e2x.org
On a commercial extension an open-ended name looks unfinished. On the .org it looks like a body with a broad remit, which is exactly what those bodies have. Same characters, different impression entirely.
That matters here because the X is doing deliberate work. In technical and business shorthand X is the variable, the anything, the placeholder: V2X, X-as-a-service, power-to-X. A name ending in X reads as intentionally open.
E2X therefore says from energy, or education, or evidence, to whatever comes next. For a research body, a foundation or an initiative running several programmes, that flexibility means one address covers the portfolio without a rename when priorities shift.
Three characters, a recognised convention, no competing usage.
Offers considered.