Can you do both? Fast compile time and slightly slower execution time for debug build using dynamic dispatch and long compile time and fast execution time for release build using static polymorphism from the same code base.
Recall that dynamic dispatch does not need you as a programmer to know which implementation is being used for a given polymorphic method or function - I find it difficult to see how the compiler would be able to reason what implementation is being referred to in code to generate static polymorphic code without the programmer being explicit. If that were the case, there would be no need to be explicit at all (and consequently no need for static dispatch in Rust code), and all you would need to do for polymorphism is to use dynamic dispatch. However, although this would be incredibly convenient and ergonomic, unfortunately the Rust compiler is not capable of magic.