Is someone who has a business and deals with chometz allowed to place an order on Chol ha-Moed Pesach by a goy for chometz that has not yet been created and that he won’t receive until after Pesach? (of course in a way that on Chol ha-Moed it would be permitted, i.e. davar ha’aved or another reason.)
Interesting question, to which I do not know of explicit sources.
The only apparent problem is that the buyer will want the chametz to be in existence (rotzeh be-kiyumo, which is a problem according to the Tur and most poskim, though the Peri Chadash mainatains that there is no problem of rotzeh be-kiyumo in chametz).
If the chametz has not yet come into existence, there will not be a problem of rotzeh be-kiyumo for “chametz on paper,” but if it will be coming into existence during Pesach, this will be a problem even though he does not yet take ownership of the chametz.
[In addition, if the chametz will come into existence during Pesach, and payment is made in advance, some maintain that this involves a kinyan; I understand the question refers to cases where payment is not made in advance.]