I used masonry-face fixing joist hangers, rather than a wall plate.
Four 10mm fixings (multimontis) per hanger. Used a 4-hole jig, slid
along a temporary batten to ensure accurate placement of hangers. With
modern tools and fixings it's both quick, and results in the loads
spread over many more points in the masonry. Only downside is the cost
of that many masonry fixings.