I know those items (factorio-logo-11tiles and wube-logo-*material*) are marked as hidden and cannot be spawned, even within the editor (as far as I know) I would like to make some menu simulations of my own and would be nifty to have them seamlessly incorporate within the others by adding the aforementioned entities.

EDIT: nevermind, they are available but only within the map editor > entities section, and not the regular inventory > unsorted category (despite the fact it already has other editor/debug-specific entities there)