Think it okay every once in a while, consistantly maybe not as much. SuperLuminova and Lumibrite do have a finite life. I would say every once in a while is okay. However sunlight is much more intense... meant that tongue in cheek, now feeling so low I could play handball against a curb...So it's a bad idea to charge the lume with a UV light?
I do have older watches with lumibright that do not glow as intense or long as they once did, but they're 25 - 30 years old.
I do charge my rolex and omega's occasionally, but not every night. However services typically involve dial and hand replacement...