Go Fever
I wonder if the mad rush to the first Starship orbital launch is for a "in your face" directed at Bezos' for his argument against SpaceX selection being that Starship is an unproven platform. Its looking like booster 4 will fly before the 20 engine thrust simulator is finished for use on booster 3.
After the final stacking yesterday they rushed to install 29 engines in well under 24 hours before even finishing the welding.
They probably know enough from the completed tests to be confident the booster will survive launch. And since they aren't going to try catching it, the other testing can wait. I guess the test is more about advancing the Starship design than the booster.