Offer type to discount the first X matching products

I was having problems trying to make a promotion that would apply only to the first X matching products in a cart.

The promotion offer that comes with commerce will apply to ALL matching products. There is a limit for quantity, but this is for the quantity of a line item, not how many line items it applies to.

What I want is to apply a promotion to each matching line item up to a certain amount. (only the first 2)

So say my cart has 5 qualifying products in the cart, I only want the cheapest 2 to be discounted.

Not seeing a clear way to do this, I have written my own offer plugin that does this, I can create a MR if this is something you think you would want to add to commerce.