When using the settings to not automatically split backorders in pick status, it puts the order on hold. When deciding from there to split the backorder, the new order that is created will be unapproved, even though the original order was fully paid and the payment is taken across to the new order. This seems to be different from other processing rules within neto.
Given that this functionality has been like this for sometime, i would suggest putting in a new configuration to allow clients to have the newly created backorder be auto approved if the order that it was created from was already approved.