I love this question. Through my work at both Salesforce and Shopify this is something that comes up regularly because of our platform and healthy partner ecosystem.
If the answers to questions 1-3 are yes, then it warrants a discussion with your team. The key question that decides the outcome here is #4.
Is it worthwhile for you to invest time and resources into building this thing? Does it unlock new value or strategic advantage that you do not have by offering this through a partner?