Still not worth it aside from the "neat" factor. 3 watts net increase won't pay for the cost of the fan over the lifetime of the panel, and a moving part like a fan won't make it to 25 years (5 years if it's lucky).
I suspect biggest failure mode for fans are the bearing’s lubrication drying out. Sometimes this can be serviced (with much difficulty) or take the efficiency hit and use a thicker grease that doesn’t evaporate as fast.
Nice thing is that they’re not a critical part here, and it’s diminishing returns so if you have multiples and 1 fails, you’re still ok.
Probably depends a lot on the specific climate though.