With the many characters in the franchise having different appearances over the years, I was wondering if we may see costumes and cosmetics, either as unlockables or DLC, available in the game? Hopefully, each costume or cosmetic isn't treated as like a separate character but something you can easily switch when you select that particular character like when you go into the costume section of a particular hero in Marvel Rivals. Some costumes could even be more than just a simple reskin like seen here Gordon's original "toy-like" design in the very first edition of the RWS The Three Engines illustrated by William Middleton. Not to mention if Henry were to be added then you could switch between his original and default overhauled design.
I had one idea for the cosmetics where they all take place at the works, like prompts similar to in-game mission icons so we can hop in straight from Explore Mode. Now it's unlikely we could see physical cosmetics like snowplows, but I wouldn't mind alternate paintjobs for the engines like James' black livery.
Now, this is probably an implausible idea and one that will likely never happen, but I've always thought it would be cool if Dovetail added a toggle that could switch every engine and piece of rolling stock between their TV Series and Railway Series appearances. That way, players could experience both versions of Sodor in the same game, choosing whichever style they prefer. Not only would it be a great way to celebrate the franchise's history, but it would also appeal to fans of both the television series and the original books. It would essentially give us two distinct interpretations of the same railway without having to create a separate game for each one.