I tried making an ascorbic acid print developer. It required hydroxide to get proper activity levels and would develop fog no matter the restrainer I tried. If you over exposed the print and then pulled early you could get a somewhat reasonable cool brown-black tone results though. Also, since I'm working with food grade ascorbic acid and food grade propelyne glycol as a solvent to make mixing easier (possible to get at least 8%) I decided to taste a drop one time after mixing. Like taking very sour and slightly bitter oil and putting it onto your tongue, and a taste that sticks with you for an hour.
I'm more interested in an edible print developer than a film developer. Ascorbic acid can be powerful enough especially when adding lye, but to control fog you need a bit lower pH and some ingredient to replace phenidone. With AA, phenidone, and carbonate I was able to make a very good neutral tone print developer. Phenidone though is of course not something you want to eat, even if it is less toxic than many other developers. Also, oxalate seems to be capable of making ascorbic acid last longer in solution (kinda as a sulfite replacement) but even if oxalates/oxalic acid is present in many foods, it's definitely not something you want to go out of your way to eat.