The platform question, answered on integration. One argument against Shopify for this catalog comes from Shopify's own help center: "Some integrations in the Shopify App Store aren't fully compatible with Shopify B2B, specifically companies and catalogs." That is a warning about integrations, so the question is whether yours writes to companies and catalogs. Integration runs through an owned Uncap Connect app embedded in Shopify, or a managed iPaaS integration. On the Connect route, Uncap Connect runs inside Shopify with no separate middleware to maintain, keeps pricing, inventory, customers and orders in real-time, two-way sync, and syncs "customer-specific pricing, credit terms, and tax rules." The ERP stays the system of record. Where the compatibility and gating rules live, in the ERP, a PIM or Shopify, is decided in scoping.