With a Meshtastic antenna the advice is to put it as high as you can with as few obstructions as you can manage. For my home setup that meant a few physical iterations as it went from inside my office, to inside the attic, to outside the attic below the roofline, and finally outside the attic and higher than the roofline.
As an engineer I want baseline quality data before I make a change, so I know if my change helped, did nothing, or actually made things worse. I don’t have the knowledge or the tools to really measure the quality of my antenna setups, and I want real-world connectivity metrics more than I want a gain measurement.