Good to know! The seats look so squished I am genuinely concerned with long term damage
Don't worry about it. The cushion will relatively even out after you take the seats out and through use. Check that the Nuna allows seat protectors. This is what they say about the RAVA seat -
Can I use a seat protector under my RAVA to protect my vehicle seat?
The RAVA was designed with a smooth seat back and seat bottom, so using a vehicle seat protector is not necessary. We do not recommend using any products or accessories that are not approved by Nuna. Adding a product or accessory could alter the effectiveness or performance of the RAVA if ever involved in a crash. We do not recommend placing any seat protector or other item under your RAVA.