OK, well you could send it back and then you would loose time that you could be flying your Mavic.
You could also fly the current Mavic and observe the real world flying characteristics and enjoy it for a while before having to send it back.
For instance if DJI will replace the Mavic within 30 days. One could fly it for say 27 days and then bite the bullet and indicate that the gimbal is misbehaving and potentially other areas of deficiency are noted.
You have documented proof that you suspected an issue as you now have video of the clicking of the gimbal. It does appear that when rotating the camera right and left during the start up calibration that it hits the stops kinda hard before rotating in the other direction , but I have seen others that have a similar issue and no functional issues are present.
If its going to bother you (and it seems like you may keep this in the back of your mind) relieve yourself of the stresses and send back for replacement. I guess its better to send it back now before the awesome flying weather is upon us.
The only bummer is that you skinned it and you would need to pull the skin and place each piece on some transfer pad so that it can be rewrapped on the replacement Mavic.