Precision 3930 Rack Spacing

Hi Guys/Gals

Just wanted to know what people's thoughts are on the need for rack spacing on these. I know typically in a proper server room rack setup servers are actually best off with the front to back airflow for cooling and gaps can actually cause dead air/hot spot and are usually better off covered with a blank

However with this workstation being rackmount the GPU has a rather pathetic little vented section on top so I would've thought it would be beneficial with these to actually leave a 1RU space clear for airflow above for the GPU

Not the end of the world just have a few racks to clean up where unnecessary RU spaces are left and even gear mounted not in the right RU holes to create small gaps and am trying to go with best practices.

Anyway, look forward to any input

Thanks