So, I am using uptocouplers and digital isolators for a project connected to a microcontroller GPIO. I removed the ground (ground plane cutouts) under the load side of the components, is it necessary to do this on all 4 layers or just on the toplayer where the components are located? I do have vias carrying the load-side signals near the components, that's why I cut away all ground. Is this correct? The PCB is meant as a control hub for an AGV with a nominal working voltage of 48VDC (battery supplied, 55V charger supplied, during deceleration or braking up to 100V). The loads controlled are various contactors, detectors and a motor brake input.