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I presume they are strictly for building purposes.

In a practical sense, prop fences have been experimented with, and shown to improve efficiency by maintaining airflow on more of the top surface of a prop.

This being said, not only is this prop not acting in reynolds numbers, where this would be beneficial, but props this small do usually operate stalled, and/or have little effect on the upper surface of the prop. Props of this size work mainly off of Newtonian principles (for every action there is an equal and opposite reaction), meaning for what ever air is pushed down (thrust), the aircraft goes up.If we were talking about a that was large enough to operate in higher reynolds numbers where a device similar could take effect, then these are poorly carried out and actually reverse of what they would otherwise need to be. The size, shape, and angle that these are mounted would in fact induce airflow separation instead. If you are interested in more information, I would look up Catto (full scale prop manufacturer) who ventured into prop fences on a few of their long endurance custom props. Not much info is published, but they do a great job at displaying the information they did manage to gather.

Anyhow, very cool looking props, and it is an interesting idea to help with the complications of the print! This comment is only to help with Prin3dXYZ's understanding, and to help answer his question.

EDIT: All of this being said, there are no studies with any such devices with these smaller and or low reynolds number applications. Strange things happen at low reynolds numbers, where a lot of traditional principles are changed, and sometimes reversed. So, with anything small scale RC, the only real answer, is to build it and test it! This is where shendriks can chime in with any information on whether there was a noticeable change.