From what I gather you are concerned about FOCI requirements for DSS.
The issue with FOCI might be on sensitive projects. But there is nothing that I could see that you can't apply for the grant and be awarded it if you are a foreign citizen or a company.
P.S. Of course I don't know if you are in one of the no-trade countries in which case ...
Virtually every public company in the US has foreign investors. That by itself does not preclude a company from getting a DARPA grant.
An example of a DARPA grant given to a company with foreign investors is the Boeing X-37 project.
Boeing is a publicly traded company with foreign investors.