The “Mark order as in progress” option was announced in Winter Editions 26 - https://help.shopify.com/en/manual/fulfillment/fulfilling-orders/single-fulfillment#in-progress
It would be very helpful for this to be a fulfilment_status we can use to query orders - (orders - GraphQL Admin)
It would also be great to be able to set this as a state for fulfilment orders, in a similar way to the local pickup fulfillmentOrderLineItemsPreparedForPickupmutation. (fulfillmentOrderLineItemsPreparedForPickup - GraphQL Admin)
It seems to use FulfillmentOrderReportProgress
It would be great to learn if this is possible.