Just for fun, I connected the tips on the last example I created. The prop consists of a mix of swept back and swept forward blades. It's performance would be similar to a propeller with all swept back or all swept forward blades. A few issues will hurt the performance of what is shown. The airfoils get close at the hub and tips, the hub has to be wider than a normal design, the connected tips extend past the diameter of the propeller. It's either extend them out or change the interior of the shape. Changing the interior would deviate from the calculated shape. Extending them out will also deviate from the performance calcs. Since connecting the tips is not of any use, this was just to play with the shape in cad. It would be better to use all swept back or all swept forward. Even better than that would just use straight blades or straight blades with swept airfoils (if sweep is really needed).

Edit; Updated pictures