I called Hi Flight and asked if they had seat foam for 350X. They said nope. Nothing like that for ATC's. After that they seemed completely uninterested in me unless I wanted to buy a seat cover.
Got a hold of Ceet today. The guy was pretty cool and didn't "think" they had seat foam. He put the manager on the line to talk to me and the guy i talked to seemed like he was the owner by the way he talked. Anyway, he was really cool and chatted for a bit. He said they don't make seat foam for ATC's right now but he has had some requests and is considering it in the future. He mentioned that he did start making Ceet covers with ATC and 250R on the sides. I told him that was a good idea, because I saw a bunch of people on this site getting excited about that. I made sure i told him i was a member of 3ww and org and i made sure to tell him that if the aftermarket companies would pay a little more attention they would see that there is still quite a strong following for trikes. He acknowledged that he knew there is a following and said he was working on some possible future stuff for trikes.
I don't know if there is anything to get excited about there but that's what i found out. So, anybody who was under the impression that these companies made seat foam for ATC's, they don't. And Ceet is the only one who seemed remotely interested in offering it in the future. Just a heads up for you guys.