Electrons are driven into a higher orbit then collapse back down and in so emit that energy as a photon of light, the wavelength of light shooting out of the P/N junction depends on the substrate, so when overdriving, if it's not damaging the substrate it is stressing it, but simply energizing the laser diode stress it, will it wear out faster by overdriving it?
It is likely, by how much we don't know, and if the cost is acceptable then enjoy it, but it's likely to accelerate degradation by some amount, it could be very little or a substantial amount, we don't know but I know overdriving LED diodes in flashlights doesn't take all that much out of the lifespan, as long as you don't go too far, I have heard of some green shift when they are pushed really hard, but I digress.
If the output falls at the tail end of the color shift then that's about the limit, if output does not fall and only color shift is observed then that's not so bad, most these diodes at least the more recent ones will dim all the way down to almost nothing when pushed to 7 amps but recover as soon as the current is reduced, that's probably not good for them, but again if the output is not falling hard as the current is increased then the stress may not be all that severe.
This is my guess based on playing with a lot of decommissioned diodes, a theory that would show up in the raw output is that the dominant center wavelength is full and the adjacent bars are getting more of the load, if you look at how the raw output fills in on a wall as current is increased you will see it starts in the center and spreads out, so maybe that's a part of it? Probably not as the adjacent bars are higher frequency/darker blue.
