When Intel issued their end of life notice for the ZR300, they recommended to manufacturers that the replacement should be the D430 camera module, which is the camera circuit board inside the D435 camera model.
The D435 model is better at tracking in motion than the D415 because the D435 has a fast 'global shutter', whereas the D415 has a rolling shutter better suited to scanning stationary objects. However, the D415 model tends to produce better quality depth scans than the D435.
The ZR300 SLAM library would not work with the 400 Series cameras. A new RealSense SLAM Vision Library is being worked on.
Until that is available though, I recommend the open-source ORB-SLAM2 system.