As promised, here are some photos of the fix. I ran out of daylight so it will be finished tomorrow but this shows the progress. You can see the amount of bowing out and how much the legs leaned outward in the one photo. I drained the pool down to about a foot of water and then dug around the underground supports of the uprights. They are sitting on a mixture of sand and dirt so its no wonder they settled. I dug down enough to place a section of a concrete paver below the arm of the leg. I still need to take a trowel and get them fully placed and pack around them with dirt but its already showing improvement. I was able to get 2 of 3 leaning legs straightened. My only concern now is that the plate on the inside below the liner didn't sink down like I had hoped. I'm going to explore some options tomorrow after I completely drain the pool so I can maybe shove some sand under the liner from the outside, although I don't know if that is even possible. Anyways, I'll post more pics from tomorrows adventure.
Finished up the fix yesterday. I added gravel and paver blocks to each side support and then packed them with the dirt/sand mixture to get rid of any voids. The next step was to try and fix where the pressure plate was creating a rather sharp ridge under the liner. I used a piece of wood with rounded edges and a hammer and pounded the wood in horizontally about an inch below the wall. This pushed the sandy pool base up in the area next to the pressure plate. I kept doing this until I had about a 2 inch by 12 inch mound of sand below the liner. Then I removed the wood which left a void below the new mound of sand. I then used a garden trowel and packed the void with a clay and sand mix that was leftover from fixing the walls. The final step was to get in the pool and carefully massage the mound across the pressure plate edge until there wasn't a ridge left. I was able to push the pool cove base back into position and smooth out the edges. The pressure plate is still able to be felt through the bottom but at least there arent any sharp edges. When I eventually replace this liner, I'll dump some more sand inside and bury the plates so they don't interfere with the bottom. The pool is currently filling so wish me luck.