Mews Commander gives you 2 status options upon creating of the new reservation:
Optional: The booking is not yet confirmed but is blocking space on the timeline and availability. No revenue is posted in revenue reports. If options are cancelled, no cancellation fees will be incurred.
Confirmed: Bookings that are confirmed will display on the timeline and have revenue assigned. If cancelled they may be liable for cancellation fees, depending on the rate type selected.
With this said, we do not give an option to change reservations back to the "Optional" status.
NOTE: It takes a conscious decision to confirm a reservation and guest's agreement with possible cancellation fees.
From accounting perspective, it means as well that there will be future revenue recorded in case of Non-Refundable reservations and the ones within a window of penalties.