Setback!
I spent a good deal of time assembling my two new sawhorses from Harbor Freight. The plywood atop them is one of the (very heavy) 3/4" sheets for the floor.
Day 3 should have ended with the build looking sort of like this.
Except I miscalculated the positioning of the joist hangers, and the floor joists all ended up being about 1/8" to 1/4" proud of the rim joists. GAY!
The joists ought to look like this when done.
The exemplar joist set-up I made from a spare hanger and two scraps.
I did get all the floor joists to come out the same length. Hurray for the mighty Hitachi CMS! Now if I can pry up the hangers and reposition them (probably on the opposite face of each board), assembling the floor will be a snap. The other setback I discovered has to do with the positioning of the blocks - they seem to be too close together somehow. I don't think it's enough of an error that I'll have to dig out two and move them. I'm going to put together the floor frame and see how it sets on the blocks as they are.