I can't see that that particular brand is available for a shotgun but I would steer away from them for use in shotguns for the following reasons,
(within reason) the tolerances of the chamber of a shotgun is not material to its ballistic performance so the laser cartridge can easier sit out of alignment with the barrel. The chamber must account for tolerances in cartridge manufacture so it is likely to sit off center.
If the laser in the cartridge is not perfectly aligned with its own body that error will be amplified.
In short if any alignment is off by (say) 0.5mm over the 3 inch cartridge length if the laser cartridge that could easily be 20mm at 3 yards and 20cm at 30 yards. If the error is left to right, you could end up with a difference in lead on a crosser of 40cm which is a pattern. In short it could easily make you worse. I also think I am being generous with the potential for error.