Yes.
Next to the EFIS option in Map Mode is a gear icon. If you click on that you can select Default To Fullscreen Mode. Or, when you start EFIS you can click on the EFIS map itself, and choose Full Screen Mode.
[Brian, an unimportant nit to pick: as noted above it's "Fullscreen" in the EFIS settings menu, and "Full Screen" in the EFIS popup menu.]