This plugin allows you to:
vendure-config.ts:Maximum amount per order and Multiple of per order on a variant and update the productYou can fetch product.limitPurchasePerMultipleOf and product.maxQuantityPerOrder via the Shop API to display messages on your storefront accordingly.
V3 removes the fields from the variant and places them on a Product, in a different format. This plugin isn't used much, so there is no migration script available. We do it manually:
onlyAllowPer value per ProductVariantonlyAllowPer of a ProductVariant per Order