Where I work, we are transitioning to a Agile methodology for our software development. We would also like to explore the same for hardware development, but the mental impedance mismatch might get in the way. Specifically, a big part of most Agile methodologies is that you work on a prioritized set of features. In software, that's fine because you can always go back and refactor/rework past code. But in hardware-- at least for a large, sophisticated design-- means you're respinning boards at each iteration. Or, you're building your system around programmable logic.
So why not just start with (and end with) a FPGA-based design? Well, as a software engineer I have no problem with that, but sometimes the hardware folk have legitimate reasons not to. But putting that aside, I'm curious if developing with a FPGA for speed and agility but at the end of hardware deelopment transitioning to discrete logic is something that is commonly (or at least sometimes) done.