A Shopify plus store has to product types (A & B). We need each product type be charged by a different payment gateway (Gateway A & Gateway B)
Depending of the product type in the cart, then the Gateway should be the specific for this product.
Product Type A --> Gateway A
Product Type B --> Gateway B
This can be done in only one store developing in the checkout for a Shopify Store?
Yes, you can use Scripts on Plus to toggle the payment gateways based on the product type.
This example should help: https://help.shopify.com/en/manual/checkout-settings/script-editor/examples/payment-gateway-scripts#...
You can match any product by type, this is exposed to the product object: https://help.shopify.com/en/manual/checkout-settings/script-editor/shopify-scripts#product
You can hide any payment gateway you have installed on Shopify based on custom logic.
Hope it helps