Question dunning of negative amounts

In our system we have set the amount limits for dunning procedure at $60.

But we are observing credits going thru' dunning process. We see this behavior for Security deposit refunds (doc type IN) & transferred credits (doc type XF).

Example of credit through transfer going thru' dunning :

Example of Security deposit refund going thru' dunning

Is the total balance on CA considered during dunning or amount at document level ? In the 2nd  example, we have a debit balance of the account.