simplicity of sending a guy up on a cherry picker when needed (ie not that often). Specially given that easyjet's maintenance is subcontracted anyway.
I think you answered that yourself.
If needed renting some hangar space at other airports may not be that expensive on an ad-hoc basis when needed.
Anyway I think they are more enthusiastic about the glasses, think the want to add all AMM procedures to it. And have it identify the various elements of systems for easier recognition.