Early development phase

That depends upon your system.

A dev kit could help to walk the first steps with a new os. you would need to configure the board depending stuff and let the software guys run. later if the target is available you create / update the board depending files and update the software guys with new targets.

that what we did. so the software department was able to start with the os, implement the application and some drivers. it was also possible to implement some ip functionality that needs the os & app.

when the targets arrived we needed to finish the target depending development but the main job for the target was already finished

the dev kits saved a couple of weeks on the overall time line.