We need the ability to apply a coupon code when editing a sales order that was converted from a quote, without having to use 'Recalculate totals.' Recalculate the totals could overwrite the original price if it has changed or it will recalculate the discounts.

Currently, quotes don’t support coupon application, and when a quote is converted into a sales order, we’re prompted to recalculate totals to apply the coupon.

The issue is that we can’t apply a coupon during the quote stage, and when we try to apply one after conversion to order, recalculating totals causes other pricing problems.