I should have added my Mapleshade stand improved the sound of my system.
The fact is most rooms are far from ideal listening rooms, so compromise rules the day
I have a decades old vertical Solid Steel vertical rack, but have long wanted to replace it with a horizontal rack, but quality racks are $$$$! Recently, I moved mine ~ 4ft back, very close to the front wall. That helped a ton. Moving the speakers well out in front of the rack helped quite a bit, too
As to how much any rack interferes with the imaging might be offset by the extreme high price of either high quality speaker cables, or interconnects. AND, if the rack is to be placed along a sidewall, what about side wall reflections?
One inexpensive tweak that really works is/are Machina Dynamica Springs under everything