1. The RealSense 400 Series actually works excellently when the fields of view are overlapped. The cameras do not interfere with each other, and more comprehensive depth data is captured because the overlapping fields mean that there is redundancy in the data.
2. The RealSense SDK 2.0 software used by the 400 Series allows an auto-exposure Region Of Interest to be defined on an image. In this region, the intensity of pixels is averaged and then the SDK tries to maintain the value at a pre-defined setpoint. This may provide the highlighting that you need.
Page 2, section e of Intel's camera tuning guide has more information on setting up the ROI.