Lower midline is slightly off & causing my bite to be off?

[ArchWired28]

Well, it is my understanding that the movement that is possible with elastics will always be relative, the upper teeth move one direction and the lower - another. That is because it attaches to the teeth only. However, with the class II elastics upper arch moves more that is why I am thinking he did not give it to you. I am again guessing, that with this elastics configuration you will have less movement of the upper front teeth, and more of the premolars and canines. Wear it for some time and see what it does and how you feel. I undrstand your concerns about relapse but that is probably correctable later on.

If you want to move one arch only, something else must be used such as TADs. But that is rather extreme. I am not sure what the deal is with cutting the archwire, never had it done.

Maybe you just need additional IPR done on one side on the lower teeth to create space and push them forward?

Sometimes, perfectly centering the midlines may not be possible or very hard to achieve. I used to stress out a lot about this and also about my bite (that still does not feel right, but it is always changing so I dont know what to blame it on). But step by step I realized that perhaps I had crossbite for a reason and now when it's all sorted out, ideal occlusion or looks may not be possible due to the build of my jaws and teeth.

As I said, don't give up just yet. Wear this elastics, see what it does. If you are not happy, bring it with him next time. If still not happy, get the 2nd opinion... There are options, but also limits on what can be done. I wish you all the best!