Hello; Unfortunately I have had tanks on hardwood floors. a 55 gallon leaked most of it's water on weekend when I was away. The floor did not buckle but was discolored. Not sure if it could have been made right as I never tried. My take is that most any kind of flooring that is real wood or a natural material like bamboo will deal with occasional and tempory dampness, but not long term being wet.
I understand the plan is to only have small spills that are soon wiped up, but it has not worked out that way for me. I have had a few major leaks. I was lucky with one in that it was in a basement with a cement floor,so no damage. Mostly there are small leaks that persist over time. Some have gone unoticed for a long time with the potential to damage wood flooring. The problem is that the wet gets under things like stands and pads and stays wet. Wood floors look good but I am not comfortable with it under tanks.
When I moved into my current house I took up the carpet from the area around my tanks. I put down vinyl tiles. I also made a border around the area with plastic quarter round to hopefully keep the water from the carpet. I took advantage of a hole thru the floor so that a big spill will go into the basement.
About the denting of flooring. For metal stands i put pads under the legs to spread the load. The heavier the tank the bigger the pad. I like solid material like aluminum. I used plastic furniture pads in the past but the metal legs over time pressed into the plastic. A metal pad/shim under the leg and then on top of a plastic pad should work. I no longer used wood pads under legs as they can get soaked from leaks and not dry out for a long while.
Good luck
