It raises an interesting strategy topic in regards to booking awards:

Book 2 one-ways at some sort of premium - but it gives you the flexibility to edit travel dates, shop for other one-way awards after booking to see if you can secure a better one way rate, or a better overall routing/equipment. Most of these via a cancel, redeposit, and re-book function. But you might be able to do some of this via a schedule change parlay.

Or book a single round trip and grab the discounted miles cost, and lose some of that flexibility.

I don't have a feel for what sort of "premium" I would be willing to pay, I guess it would depend on each award search result?
5% premium, sure I will pay for the flexibility, 25% I might bite the bullet and do the RT booking.