The punishment dealt out by states is far more unfair and harsh than anything you will see in a tribal setting. There's no dilemma there, leave them alone.
They don't want your help, and just contacting them can kill them because they don't have any immunity to common diseases of civilization. An invitation to enter civilization means becoming a beggar, slave or prostitute if they don't die of a simple common cold. Forest people aren't smaller because of malnutrition. They are smaller because that is a helpful adaptation to their environment.
If they want contact they will seek it.