Three characters on the .org, and the X at the end is the useful part. 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 deliberately open-ended.
E2X therefore says: from energy, or education, or evidence, to whatever comes next. For a research body, a foundation, or an initiative working across several outputs, that flexibility is a feature rather than a vagueness. It lets one address cover several programmes without being renamed.
The .org gives it the institutional read that makes the abstraction work. On a commercial extension an open-ended name looks unfinished; on .org it looks like a body with a broad remit, which is exactly what those bodies have.
Three characters, a recognised convention, and no competing usage.
Offers considered.