My job was related to plastic injection molding, and usually, the number that can be read on a plastic part is not the batch number (it would be complicated to change it on the mold for each batch), but the number of the mold cavity (the ‘print’).
Imagine a mold that produces the Anafy propellers, it could be constituted of 8 cavities that would allow production of 8 propellers at a time for each injections.
Let’s say 4 props left and 4 props right.
Each of 8 props would have its own mark (1/2/3/4) and a left or right triangle to indicate CCW or CW props.
The advantage of invidual markings is to know if a dimensional problem occurres or a thermal problem, which props are affected to allow proper modifications on the mold.
So my guess is you can mix numbers (but still be careful with the orientation of the triangle that states the rotation direction of the prop)