I think you might have to reveal the relevant sources to the people evaluating your grant, tho. They should be able to contact anyone applying for a grant to get more information. And a person should be named on your results as your evaluator to discuss the results with.

That's one reason why I think the evaluators should be paid, if the process is transparent. It raises confidence in their professionalism and fairness, aligns their incentives with those of the applicants, and compensates them for doing all of this work in public.

They become mentors, rather than mere judges.