Floor frame for 8' wide shed is 3" too wide on either side
structurally it looks ok. (assuming you'rte going to fill that 3/4&quot; gap or put blocking in there)
8'x13'5 was going to take 4 sheets of plywood sheet 8'5x13'5 is still going to take 4 sheets.
Either use the off-cuts to fill the ends or join sheets end to end