In general, BC Framer® and BC Calc® will not accept lengths of cantilevers that exceed 1/3 of the total back-span length for all joists and beams.
In addition, the following limits apply:
BCI 4500s 3' 0"
BCI 5000, 5000s 3' 6"
BCI 6000, 6000s, 6500, 6500s, AJS 4' 0"
The limit may be over-ridden but the designer will be responsible for verifying that the members with long cantilevers are properly designed and braced.