In many respects, we shouldn't have to be dealing at all with these issues (problems) of "more even light distribution' and having to raise lights to the top to get better "penetration!" It's something that manufacturers could easily fix.
There needs to be many more lights available with actual even light distribution over their coverage area from the very start. For ex., a fixture designed to cover a 4x4 space should have the same PPDF/DLI/PAR/light intensity at all points in that space at a typical height in a typical tent. We shouldn't even have to look at PPDF maps of light coverage. Whether through better LED placement (fewer or lower power in the center), angling/aiming, lenses, reflectors, etc. this is fairly easy to do. It seems crazy that even leading light companies still put out the same old designs that concentrate intensity in the center, such as quantum boards with evenly spaced LEDs.