I'm responding to this as a former caregiver for adults in a group home setting. I had three confined to wheelchairs. And every time one of them needed to replace or upgrade their cushion, we would get an order from their doctor for occupational therapy. We had to occupational therapist evaluate their chair, their postures, their ability to reposition etc. And the therapist would recommend anywhere from two to five cushions, we'd choose, they'd order, and insurance took care of nearly all or entirely all of the cost. It takes a little extra time, but I recommend it if you can go through the process.
I hope you get some good feedback and get comfortable soon!
💜💜