In the past I switched the implementation of the zoom page transition because the performance of the old transition was terrible, but I'm hopeful that with Impeller we'll be able to identify and fix the issues that made it so slow. In order to evaluate this though, we need to be able to opt into the old transition for benchmarks on CI.

https://github.com/flutter/flutter/issues/129742
https://github.com/flutter/flutter/issues/121325