I realize there was never a handicapped sign block for the 1x1f, but since the bricks use the same aspect ratio, shared decals will look fine on either brick and give people more options for construction.
For reference, last time I checked, both the 2x2f and 1x1f print tile use a 1:1 aspect ratio, the 1x1 and 1x4x4 print blocks use sqrt(2):1 or something pretty close.
EDIT: I just realized that would mean the borders on the decals would be scaled down on the 1x1 but I'm sure there's some way to handle that.