Memory is the scarcest ressource of embedded and restrained devices. This paper studies the memory footprint benefit of pre-deploying embedded Java systems up to their activation. We find out that the more the system is deployed off-board, the more it can be efficiently and automatically customized in order to reduce its final size. This claim is validated experimentally through the production of memory images that are between 10% and 45% the size of their J2ME CLDC counterparts, while using the J2SE API and being ready-to-run without any further on-board initialization. Embedded solutions like J2ME degrade the Java environment and API right fromtheir specification, limiting their usage perspectives. By contrast, our romization scheme generates and specializes a custom-tailored Java system and API for embedded applications being deployed in a full-fledged J2SE environment.