I imagine that from engineering POV, having self-replicating cells that will also do the useful work won't be optimal. This self-contained single-cell system was the only one that could work in the wild initially, but after a while even in natural systems like our bodies we have cells (like those red ones from our blood) that are produced by specialized tissues (red bone marrow), are designed with a specific function and with a simplified structure (like to be small, without cell nucleus), and disposed by other specific tissues (in the liver). If I had to design a system (and a business) it would involve printing specialized (non-replicating) work cells and some control/disposal mechanisms. The research focus on simplest living and self-replicating cells looks interesting but not that much oriented on any practical purposes.