Judging from the pictures of the strings, you got the dish assembled as well as possible without the center plates. The plates are added support and they help bring the ends of the panels together even all the way around. I've seen a lot of installs where they were left off and the dish performed like a pro. Nice job. Too bad you didn't have a better view of the sky from your location. Pretty much everything we watch is on 4 satellites, all high in the sky, and with a little effort, you may be able to clear a path to them.
I had a few branches that grew out in the way of the dish when I lived at another location. I did a little long range branch control with a 12 gauge shotgun. Works really well for removing branches up to 1 1/2 inch in diameter, if you live somewhere you can take them out with a 12 shotgun.

Neighbors frown on that in a populated area. It kind of spooks them when shot rains down on them even though it doesn't have enough momentum to raise a welt on them.