GraphQL version of NetSuite billing to Shopify billing (add) does not honor the Amount mapping

I turned on the GraphQL version of the NetSuite to Shopify billing sync, but it is always marking the orders in Shopify as paid in full, even if the Amount is specified in the mapping.

In the REST mapping, it works properly - recording only the amount of the invoice in NetSuite.

Is it because in the GraphQL mapping it's to capture_amount? But that's hard-coded and I can't modify that.

It looks like the orderCreateManualPayment mutation does not use the amount/currency variables so it defaults to the full amount when Shopify received the request. Is there a reason that this would not be using the amount from the mapping in this?