Issue with payment deadlines and Shopify Pay/Credit Card payments

We have an issue in our B2B Shop and also the Shopify Plus Support can not offer a workaround, so i am checking here if anyone faced similar issues and solved it:

In the company profiles the due dates for the payments are set to 15 days, as mainly B2B customers pay via invoice. Now we activated Shopify Payments and pay by credit cards, and we have the issue that the credit cards payments and Shopify payments are not processed immediately, but also now with a 15 days delay, which we don’t want. We need the payments to be processed immediately upon purchase and only pay by invoice with a 15 day delay.

Shopify said this is expected behaviour and we would need to make the payments in the orders then manually, but this is a lot of work. So is there any way to separate those payments methods and the due dates from each other any apply different rules to the payment methods to be processed?

Any help is appreciated.