Figure 18 of DCA6 prohibits attachment of the ledger to an overhang or bay window. Does this include small cantilevers on the house such as brick ledge cantilevers or cantilevers to accommodate exterior insulation?

Yes. Any cantilever of the house floor structure over a bearing wall in which the house bandjoist or rimjoist does not have full bearing support would qualify as a cantilever per DCA6. In such cases, a non-ledger deck or engineering evaluation would be required. Where the house rimjoist has full bearing support of a wall or foundation (such as that shown in Figure 14 of DCA6), the vertical load path is continuous, consistent with the design assumptions in DCA6.

Residential Wood Deck Design (Structure Magazine) April 2017 based on DCA 6-2012 IRC Version