I have had the same cover attached to the back of my house for almost 2 years. It is mounted in the vertical position, about 3 feet above ground and under the protection of the roof eves. I have two V3 cam power adapters plugged into two smart plugs. No issues at all.
I think that’s a good move, and I feel better about the longevity of your installation, even without the Outdoor Power Adapter. Nice work, and thanks for sharing the follow-up photos! 
Nice results. Looks like the hanging excess cable can be tucked in on the right side of the power adapter inside the cover housing.
Good idea!