Hello,
There's nothing wrong with that Coupler

.If you ever have to go this Route,I'd do this: Take the Set Screws out,and appy a Small dab Of "Blue Loctite" on the Threads of the set screws*(Strip your cable First and have it ready to insert the cable in "One side of the Coupler Only)!The Loctite can Dry quickly/and it's not Cheap.Tighten the set screw down Tightly.Do the Same for the Other side

.
A Cheaper alternative that I've used before,was to have a can of Spray Paint handy and you can mist the threads of the screws too...Works fine

.
Do Not leave any of the Copper Stranding Exposed exposed on the Coupler.
"Take Your Time/ Have Patience". Make sure the cable insulation is "All the Way In the Coupler".
So many times I've seen Installs w/copper stranding exposed from a Mechanical Crimp..//content.invisioncic.com/y282845/emoticons/furious.gif.fc81ca146dbff91fede3ed290dbc4f4c.gif .No reason for it if people would use some patience.Once someone gets into doing Proper Termination...It becomes much easier and one gets Proficient...And the end results that you did are Rewarding

...WoooHooo!!!!.
Last...But Not Least..is to put Shrink Wrap over the Coupler leaving an 1" on either side.I like to use Adhesive/Dual Wall Shrink Tubing on my cables.Once heated,the glue melts inside the tubing and holds firmly to the coupler and cable and are waterproof.
It can take more abuse and is more durable than regular shrink tube.
Sorry for the in depth....Just trying to Help.All the Best with your System.
Kind Regards,
*[Tinkker]*