I do agree that eyelets must make a difference in stregnth at the spoke holes when it comes to box section rims, especially the very lightweight ones where material is not thick for most of the section of the rim. but I don't think the same applies to C&V aero section rims where more aluminum material is usually present at the rim's inner center line where the spoke holes are located, so we can't make an assumption that all rims without eyelets are no good.
Double eyelets should make for even stronger rims than single eyelets as the loads from the spokes are distributed through a larger area....