Using a miniature BNC connector on a PCB to measure high-frequency content with an oscilloscope
You might consider adding an attenuator probe to your PCB consisting of a single series resistor. The 50-ohm coax cable to your oscilloscope can be any length - the oscilloscope input at the far end of this cable must be 50-ohm-terminated, not left to its default 1MEG



simulate this circuit &ndash; Schematic created using CircuitLab
The series resistor Rs will load the MOSfet gate driver only when the coax to the 'scope is connected. This resistor, combined with 50-ohm 'scope termination is a wideband attenuator - its attenuation should likely be made an easy-to-calculate 20:1 or 50:1. You should be able to arrange the short PCB path from Rs -to- coax connector to have 50-ohm impedance to PCB ground plane.