It would appear, then, that total inclusion types are neither scholars nor practitioners. In the alternative, perhaps Fagan has simply not encountered these folks or read their works.
The Age Focus
The claimed necessary circumstances for transfer vary. Sometimes it is a matter of a minimum age. Some ATC representatives simply emphasize that transfers should be “older” (NRC, 2013). Other ATC members concentrate on an age below which transfer is unacceptable, such as 12 due to ramifications of incarcerating these youths with adults, (Deitch, Barstow, Lukens, & Reyna, 2009), or 13 due to CST concerns (Steinberg, 2000; Steinberg & Cauffman, 2000), or 14 due to culpability limits (Hoeffel, 2013), or 15 due to fairness requirements (see Drizin & Tanenhaus, 2002, p. 690), or 16/17 due to a desire to preserve “life chances” (Zimring, 2000a, 2000b; see, also, IJA/ABA, 1980, pp. 15-16; NAC, 1980, p. 303). Feld (2000) identified the choices as among 14, 15 or 16 years of age (p. 112). More recently, Feld chose a minimum age of 16 (2017a). The ABA originally recommended 16, but later reduced it to 15 (Flicker, 1983, p. 11). DPs admit that youths “as young as 9 have the capacity for intentional behavior and know the difference between right and wrong (Steinberg, 2000, p. 6).” More important, perhaps, nearly all transfers are at least 15, and the vast majority are either 16 or 17; ATC age-related limitations, then, are mostly irrelevant, if not unnecessary.