Yes, that >= would be key. Otherwise you'd have to hit the comparison dead-on every time, and once you miss the first one there is no way to recover, as the difference would just keep increasing.
"a different MOSI pin for my DAC", nope, SCK/MISO/MOSI come from specific hardware pins. Only SS can be elsewhere.
Glad its working for you. I missed the post on the 10th, would have answered.