I'm sympathetic to the terms of a non-fundamental research program funded by DARPA. Easy street with that agency is to get designated as doing fundamental research. If you aren't at a university, that is an uphill battle that most prime contractors won't be willing to deal with.
However, the pre-pub regime is not impossible to live under. You'd have to do something like: have a private repo/branch where you do the work that's funded by DARPA, rebase constantly against the public branch, and send once a month public release request with a diff to merge into the public one. Probably after the first few months, the PM will come up with a way to streamline the process.
You lose some energy to friction, but your other option is to just not take the money at all, so it's a question of do you spend 80% of your time working on this project and 20% of your time dealing with administrative bullshit, or 0% of your time working on this project.
It's a choice that's given to many.