I am working on building a marketplace/sales channel.
We have been in contact with some folks from Shopify on the product side.
They were worried when they saw our custom checkout (PoC) and I just wanted to make sure that as long as you are making a sales channel/marketplace public app.
You can make a custom checkout (We are using Checkout API via REST ADMIN: https://shopify.dev/tutorials/complete-a-sales-channel-payment-with-checkout-api )
that we are okay? We are integrated with Stripe.