Shopify merchants: how do you check whether a promotion is actually profitable?

I built MarginBundle after seeing a recurring problem: a bundle or BOGO offer can increase average order value while quietly reducing profit.

MarginBundle helps Shopify merchants create bundles, free-gift offers, quantity breaks, customer-group discounts, and cart add-ons, then review estimated revenue, product cost, profit, and margin before publishing.

I am looking for candid feedback from Shopify merchants and agencies: what do you currently use to validate promotion profitability, and what would make a tool like this useful in your workflow?

The free plan is intended for testing one real offer. Estimates use merchant-entered product costs and currently do not include shipping, payment fees, returns, taxes, or ad spend.

Product page: https://apps.shopify.com/marginbundle