I recently watched an Analog Devices youtube video which advocated for high speed PCB ground connections to be made with a via in pad to the ground plane, as opposed to a signal layer ground flood stitched to the bottom ground plane with vias. Then, I watched another video which advocated for a top ground flood with stitching vias spaced at lamba/20 (wavelength of highest signal frequency). Which approach is more effective? Please note that I am a student and cannot manufacture PCBs with blind and buried vias. I also do not have access to impedance controlled PCBs; the best I can do is FR408.
Here is a screen shot from the video, and a link to the video for those who are interested: