Actually I'd say RSRs and Test Track are fairly similiar in length indoors v. Outdoors. Especially RSRs has some pretty slow dark ride scenes that lengthen time indoors. It's true that RSRs is more outdoors, but not by much.
View attachment 104133
The pin is where the ride building is. As you can see the proportions are pretty similiar, especially when considering the track is inflated in size because there are two cars side by side. Keep in mind that you really speed through the outdoors like TT.
View attachment 104132
Here's TT.
I don't know if this is really a strong objection to it. Especially because they could move a significant portion of RSRs indoors if necessary. I wouldn't be surprised if it was more of an OPs decision. Maintaining the diverse color schemes and rockwork in Florida where humidity and rain are a constant factor could be very expensive. Just look at what has happened to BTMRR in
Disneyland Paris. Cars Land is immense, and it's probably easier to just maintain smaller rides.
I actually wouldn't be surprised if RSRs or some other E or D Ticket ended up in PixarLand. It just isn't going to be a full on Cars Land.