I am not too knowledgeable on different encoders, but I don’t know if using cpu and gpu is an option. Av1 and vp9 are open standards, meaning basically anything can implement them, but av1 is new so older devices haven’t. The tv will probably handle vp9 fine, but I would still recommend transcoding a test video and looking if it plays back natively. With that gpu av1 is definitely not supported so I would recommend vp9.