w.r.t. Tron/Rinzler being dog coded: YES. I know people say Rinzler's a cat because he purrs, but hear me out:
They're greyhounds. If you've never been around a greyhound, they sometimes make teeth chattering noises when they're happy. It actually sounds a lot like Rinzler's purring, imo. Tron is probably a prized grade AA NGA racing greyhound, or maybe an AKC show greyhound (i.e. bred to preform, and well taken care of), Rinzler is a Galgo. (Spanish greyhound, used for hunting... I'm not going to elaborate more here because uh. TW for animal abuse--Dead Dove Do Not Eat. This is also your warning if you do decide to look it up.)
...Thinking more on this, it also fits because Galgos are smaller than purebread Greyhounds. Kinda like the height difference between Tron and Rinzler (b/c of the actors).
YOUR SO RIGHT