Customers Carrerier Account not available as Third Party under ShipStation Account

[sales136]

Now that ShipStation will be charging an extra $20.00 per month, for any other carrier account not under the shipstation account, I would like to see the option of being able to bill to the customers Account number (Third Party) as this is currently not possible as the carrier needs someone to go back on if customer account doesn't end up paying the bill. This forces us to have these other accounts added which was not an issue until now having to pay this extra $20.00. Can ShipStation have this implemented so we can then avoid even having to add these other accounts?