Hi there, @Weiners.
The only workaround we have is that add an item manually you set up as a discount to reduce the total price of all items in the bundle as what @Rustler stated.
I understand the importance of this feature for you and your business. Rest assured, I'll personally send this feedback to our product developers. This way, it might be given a chance to be added to our next product update.
You can check out this article for additional reference: Add a discount to an invoice or sales receipt in QuickBooks Online.
I suggest visiting our Blog site. This is where we share recent happenings and future developments, such as updates to newly added features. Here's the link: The QuickBooks Blog.
Please know that the Community is always here if you have other question. Just one post away. Have a great day!
