For instance, the Z9 strategy involves periods of time where some amount of fixed income treasury bonds are held. Bond ETFs usually make monthly payments to their shareholders. Does Zorro account for this income? I could not find a field in the resulting Z9.txt saying "Bonds payments received: xyz". Or maybe I missed it? How does Zorro handle fixed income bonds?

Dividends and payments are handled by your broker (hopefully), not by Zorro. In price adjusted historical data they appear as a price increase.

I see, so the price data for the ETFs already accounts for the increase due to dividends! Then it makes Zorro's and other programs lives much easier, awesome!