Not only are the Ultimate seats very comfortable to sit on but they are flat when reclined. The Ioniq 5 has support for the lower legs as well. It’s definitely worth having a look at the 5 with the tech pack and seeing if the seats suit, the boot is a little smaller but it’s still a decent size.
I'm Autistic, if I say something you find offensive, please let me know, I can guarantee it was unintentional.
I'll try to give my honest opinion but am always open to learning.
Mark