As shown in the Moreland case, it seems this is distinct from the sequential flashing of the sort observed in the Exeter case, and actually represents some form of movement around the rim of distinct plasma sources. To the best of my knowledge, there are few close observations of point source lighting. If the Villas Boas case is to be believed, his observation indicates that these are bright areas of the surface of the object rather than incandescent lights as we know them. Further, assuming the validity of the Petit-Rechain photo from Belgium, we can see that the tips of a triangular UFO show lights which may also be attributable to a plasma phenomenon. In that photo, one can observe interesting striations of density in the light, and wisps which appear to be partly detached from the source.
Beams appear to fall into two classes - normal and slow.
Slow beams, as observed at Trancas, Argentina , seem, on the other hand, in view of their slow propagation, to certainly be some sort of plasma phenomenon. Material remains luminous for some time after falling away from the object. It seems more likely that this is a luminous or molten liquid. UFOs must input energy into the near surface area to generate an atmospheric-ionization style luminosity. Further, it is possible that maintaining this ionization even when not in the full body state would make it easier to go to the full body state.