Nope. If you are in freeplay and want to change your loadout and get back into freeplay, you are subjected to four separate loading screens, two of which are often more than 3 minutes and 1 of which has about a 30 percent fail rate which forces you back to the title screen, at which point you will need to go through about four more load screens to get back into the freeplay, one of which has a high fail rate, etc etc ad infinitum.Are you able to change weapons or gear mid mission or in Freeplay?
If your luck is bad, the process of getting out of freeplay, changing your loadout and getting back into freeplay could take about 30 mintues lol.