You're missing the point. DARPA is about reaching a long-term goal -- one which isn't achievable with existing science/engineering. DARPA contracts are short term contracts whose goal is to determine why one small step towards the ultimate goal is not achievable. This is followed by another contract that determines how to facilitate the previous step ... or to determine how that is blocked. And it keeps on going!
Eventually there is success, and the success flows back to the first step ... except now you are asked to go just a bit farther to discover what the next block is.
The PM's job is to keep an eye on the overall goal & to act as a champion for the program. And, although they are generally experienced technical managers, PM's don't remain at DARPA for a long time, it's just too intense.
If you understand what is going on, and DARPA contracts are great to work on, encouraging freedom & creativity, and you'll probably get more contracts. If not then you'll end up frustrated, somebody else will have to dig through your CDRLs to get the needed data, and the followup contract will end up going to somebody who understands the process.