Looking for Solutions to Reduce GPU Sag in My PC Build

I recently built a PC with an RX 9070 XT graphics card inside a Deepcool CH160 case, and I've run into the challenge of GPU sag. Unfortunately, my case only accommodates mini ITX motherboards, so I'm unable to use standard anti-sag brackets. Additionally, the floor of the case is soft and bends easily, which complicates things further because I travel with my setup and it moves around a lot. There's only one backplate slot, but it doesn't provide enough clearance for under-GPU supports. I'm starting to consider modifying my case by adding a small metal plate underneath for support. Any suggestions?