Not into CA, but per the
IRC, this is what I will hang my hat on.
R502.6 Bearing
The ends of each joist, beam or girder shall have not less than 11/2 inches (38 mm) of bearing on wood or metal, have not less than 3 inches of bearing (76 mm) on masonry or concrete or be supported by approved joist hangers. Alternatively, the ends of joists shall be supported on a 1-inch by 4-inch (25 mm by 102 mm) ribbon strip and shall be nailed to the adjacent stud. The bearing on masonry or concrete shall be direct, or a sill plate of 2-inch-minimum (51 mm) nominal thickness shall be provided under the joist, beam or girder. The sill plate shall provide a minimum nominal bearing area of 48 square inches (30 865 mm2).
Note that the word "approved" is italicized, meaning that it is a defined term. Per Ch. 2, definition as follows.
[RB] APPROVED. Acceptable to the building official.
So not to be blunt, but I think it is due.... "It is approved because I say it is", is an acceptable answer. Simpson/MiTEK/etc. all have sufficient documentation and testing to support the design and use of their products. If used per the manufacturers specifications, it is well within my authority as a building official to accept the use of these products.