Discussion of Cash Flow implement under JDE

Let's discuss the way under JDE to generate Cash Flow.

I have read some UG docs of JDE about how to setup the cash flow, and I found JDE just uses financial accounts to divide the cash flow items , and calculate the amount using balance in F0902.

For "Cash in" and "Cash out" cash flow (usually called direct cash flow), we only need the credit accrual balance or credit accrual balance, so how can we let JDE know which side we want?

Besides, I don't think the Credit or Debit accrual balance is always reliable in JDE, for example, when Void action occurs , there will be an increase in both sides. Actually , in this case, if we see single side , it should be 0.