Niagara Position Mode Unset results in World Space rather than Local Space

When an emitter's Position Mode is Unset, the particles spawn in World Space 0,0,0. This is unexpected.

If the Position Mode is Unset in 5.4, the particles remain in Local Space, which is the intended/expected result. 

1. Create a standard Fountain particle asset
2. Put that asset into a level
3. Change the emitter's Position Mode to Unset
4. Observe that the particles are spawned at World Space 0,0,0