Perhaps useful, so just bringing it up. The #Makepad team are in their presentations always particularly proud in how they make #Rust builds in mere seconds across the full range of compile targets. They make builds after live coding *during* the presentation. Perhaps some of their methods to achieve this are applicable for you. Other than that, watching a recent Makepad presentation is inspiring, as their project is an impressive feat.
Btw, #Robrius uses Makepad and perhaps has similar approach to compiles, idk really. It is another cool initiative, who build #Robrix a matrix client with their app framework.