A drawback of that technology is the warm up time required for arc lamps.
2.
The exhaust manifold is cast into the cylinder head, reducing warm up times, so further aiding efficiency.
3.
:: : : I don't think the OP is talking about start up time but warm up time.
4.
In comparison to technologies like dye sublimation, and laser printing, inkjets have the advantage of practically no warm up time, and often lower cost per page.