Great.
Looks like fun to wear.
Have you ever worn a retainer before?
Yes, I had three different retainer when I was a Kid in the early 80th:
First of all I had a normal "Active Plate" only for the upper jaw. With that device I had no problems.
Then I get an evil monoblock similar to "Stiff Activator" but no so big. I think this was to slide my lower jaw forward. I had a lot of problems with this device. I often lost it in the night.
My orthodontist switch to a "Bite Jumping Appliance (VDP)". But my retainer has two hard metal pins in the upper side which clicked into the retainer of the lower jaw. Not really clicked, but sort of. I was able to open my mouth, but when I want to close it, I had to push my lower jaw forward.
If I remember correctly, I wore an "Active Plate" only for the upper jaw again later.
I never had fixed braces.