Using rj45 connectors for home alarm wiring
There's no sensible application for RJ45s in a proper alarm system install, unless some alarm company comes out with control panels and sensors equipped with them. The alarm you mention is not...
The sensors and control panels don't work with them, being designed for screw connections to stripped wires, and your cables should run from each sensor to the alarm control panel unbroken. Adding connectors in the middle just adds points of failure that not having connectors removes.
You chose to make some splits. You didn't have to, and it's not a best practice, which is one complete cable to each sensor, and if you have extra wires you don't need right now, no big deal, as opposed to cutting cable jackets open midway and extracting a couple of pairs, which is a hack, and an additional potential point of failure. Or chopping off the cable and having a junction to two other cables, which is a worse hack.
I can't see any way that crimping RJ45s in the middle of a cable running between screw terminals at the control panel and screw terminals at the sensor &quot;simplifies&quot; anything. You'd need to connect jacks to the sensor and alarm panel, which is still &quot;joining each wire individually&quot; and more places to fail.