Updating this because it’s been a while! We still haven’t added this to our roadmap.
As we mentioned we’ve found in testing that this behavior ends up confusing people, which is why we’ve chosen not to add it so far.
We’ll continue to leave this under review for further voting and comments.Harjot Grewal commented
Yes, I'd like for this feature as well. Perhaps have a pay date as due now by default. And allow the option to change it. These expenses won't appear on the "settle up" until that date.