Catalogue & checkout
Gambio
Variants, tiered pricing, vouchers, B2B and multilingual are confirmed feature items, which is beyond a bare variant list. But the evidence evidences no bundles, no guest checkout, and payments only as 'PayPal & Co.' — the German payment set (invoice, direct debit) is not shown, so I stop between the 3 and 5 anchors.
Shopware
The variant machinery is real — parent-child inheritance, a configurator assembled for storefront requests, unlimited property groups and multi-category products — and the checkout is documented down to payment handlers with synchronous and asynchronous gateway flows. What the captured pages do not show is bundles, tiered pricing, guest checkout, or German payment methods beyond PayPal; customer-specific prices appear only in the top Beyond tier. Checkout customisation without a rebuild is well evidenced through the plugin and Store API documentation.