Tying the rear frame rails together? Opinions please!!!

In the middle of my build, I am doing frame connectors us car tool ones, I'm going to tie the front frame rails together courtesy of Badart, what I was thinking or if anyone has tied the rear frame rails together? The more I look at full frames that they build for other cars you have front cross member, transmission cross, and rear cross making it a complete square. The more I think about it having a 3 sided "frame" would still twist easier than a full boxed in frame. So if we ran a connector across rear I would think that basically completes our full frame that's just attached to the car lol

I could just be talking non sense or something that just won't affect much performance but just trying to get some opinions
Thanks
Orangebeast