Hello Arnold,
I agree with you, the best approach is to adjust is BPC after the data load. It will tally with the source data.
I think we have the check the Account balance for those accounts Less than Zero
*REC(EXPRESSION= %VALUE% < 0 ? and then add a one more property in the account and then give the Contra account and transfer the same).
Thanks for clarifying on the best practice.
Regards,
Ram