Good explanation and even better visual demonstration. Maybe RotR involved "look like you belong there" type of sneaking.I don't know if hung up on trackless vehicles is quite it, more that happenstance led them to building a lot at once. It was the correct choice for what they wanted to do with RotR, but has severe limitations as a thrilling ride vehicle. It was the correct choice for MMRR until they nerfed some of the utility of having a trackless vehicle in the design phase. Ratatouille was a "we have money to spend" off the shelf pick, and OLC would pay whatever for the BatB ride. Then you clone MMRR and you've got six in a small window of time.
I can't go on RotR without thinking of the Simpsons between the final Kylo scene and the escape pods: