Pe,
If buying a glow engine then no, I don't want it run at the factory, or anywhere, since it will start absorbing moisture and rust. If it's a gasoline engine, and if the engine is advertised as having been test run, then that certaintly is a plus, and the oil and gasoline act as a lubricant and surface protector during shipping. If the engine was run at the factory, a faulty carburetor would have been caught in the QC, and Leigh obviously also had a faulty carburetor. BME should swallow this one IMHO, the engine was just to far off from the factory, and should be outright replaced at no cost.
DKjens