Yeah, even Adobe doesn't really use the full spec. Or at least didn't.

There's a fairly big chunk in the spec of special presentation attributes for slideshows. When I implemented them I was surprised that slide shows produced by Acrobat didn't work. Well, obviously my implementation was buggy.

Er, no, Adobe didn't use their own slide show attributes for the slide shows produced by Acrobat. They used JavaScript instead.

Oh well. ¯\_(ツ)_/¯