I'm very confused about finding BAAs. Do the Air Force, ARO, and ONR have different channels to post their BAAs? Shall I just search BAAs on https://www.grants.gov/search-grants, https://sam.gov/content/opportunities, https://cftste.experience.crmforce.mil/arlext/s/arl-opportunities? I found those three websites navigating from NDSEG's 'DoD Supporting Agencies' page. But grants.gov and sam.gov seem to include BAAs from many other agencies; does any BAA on them provided by the 3 DoD departments all qualify to be NDSEG?
Also, since one needs to choose among the three departments, is there any difference beyond finding a suitable BAA? e.g., the department's preference, their money they have to fund NDSEG, etc.