Some do heal with minimal treatment.
It is hard as there is no way to know how their life might be different with different treatment.
I do not buy into it is established that it is about delay of treatment and or severity of symptoms. There is no basis for stating that as fact although it often is done so with total confidence and accepted.
There are 50 + currently known that utilize B12 and 6 +- genetic conditions known. There is not a way to determine which are causing symptoms that may be helped with supplementation.
I have found no rational reason that any amount less then EOD should be evaluated. EOD is the logical minimum although the accepted maximum.
Why it is helpful for me to know that minimal treatment is accepted as a success is it helps to explain why some physicians and some who experienced B12D symptoms make the conclusions they do. Myopic view.
I work on not having a myopic view in that I do not state anyone else needs to self treat the way I do. I also am done with people who pretend they know what I need to heal.