datum1: according to a Peter Gerber interview 50% of freighter capacity is sold three days before the flight / only 50% of capacity is committed in a manner that allows foresight in dispatch planning.
My guess is if they can get the ~50 launch orders with one of the 'Big 3' on board and decent prospects at one or two of the other two 'Big 3', then they will feel they can at least be heading down the 'middle of the road' scenario and will give it a go.
Your historical consul/comments on launch timing resonate; albeit they appear to have little impact on a-net chatter
Probabilistically only 5x. However, you might consider significant b748f operators as key customers.
5x: The a350f platform is natural to the 5X eco-system.
datum2: UPS is said to operate "heavy" for a integrator; ~130 kg/m^3.
datum3: UPS has increased its lift, as measured by volume, by ~30% in the last ~three years... supporting Revelation's timing hypothesis.
(1) Regional buses to move volume over continental distances. Supplanted by a359p2f when available.
(2) ULR freighters to move from Asian metropolis point to Louisville point minimizing time and fuel. The b748f's carrying the bulk of daily volume as they follow the sunrise. 5X offers a competitive advantage of later pick-up times with 'clean-up' a359ULRfs positioned strategically. Further this would allow the 8's to leave earlier enabling sorts with additional time resources.
(3) b744f, age or fuel price driven, replacements.
b748f operators: Consider the thought that the global b748f fleet will consolidate over time to fewer operators as it becomes clear that the GEnX powered new build b787f is DOA* and that operating a small number of an orphan fleet has economic challenges. Airlines operating significant b748f fleets will view the a359f as a mid-capacity companion in the overall fleet. A practical example being: Fedex is committed to the b777 and b767 platforms; UPS will gravitate b748f / a359f / b767f. Other carriers will mimic the pattern that best meets their current assets.
Regarding a350-950: suspect airbus will be faced with critical feedback to increase density specs (shorten proposed length).
The long-term, a350's production lifespan, view is that this window opens a significant space for Airbus and allows carriers to view nuptials as being dynamic.
(1) A shortened a350-950f that handles general cargo on secondary (non-truck routes) and provides an opportunity for carrier dispatch to be nimble/flexible <see datum1>.
(2) Potentially an a359p2f derivative (4-wheel bogie) operating in the express market; Amazon? UPS?.
(3) Longer-term, an ultra-fan powered a35Jf attempting to displace the b778f. Technological advances providing answers to weight management constraints.
From a utility perspective, (a) a higher density than proposed a359f meets general cargo needs, (b) regional mixed density cargo needs, (c) and with auxilliary fuel tanks, ultra long-distance speed needs.
DHL is an unlikely a359f operator. Lufthansa, Aerologic & DHL married the 777 platform. Peter Gerber claimed "We have no offers" a few years ago; intimating that they were dis-satisfied with the b772f option and Airbus was unable or unwilling to build an a350 that conformed to their needs within the time frame needed. The relationship between Kalitta and DHL appears to be growing, possibly at Atlas's cost. One could hypothesis that Kalitta will use the b773ersf as a business-development/relationship-entrenching tool in the express space; DHL and Amazon. DHL is choosing to develop/pattern wide body fleet using the b777f / a333p2f / b767.
Amazon may be so obsessed with a 'disrupter' mantra that they have overly discounted the value of building long-term business relationships. Any illusion that getting one's foot in the door has a long-term pay-off conflicts with reality. This impacts projections that they would come to terms with an air-framer on price for a new-build.
Regarding the parking of 77W: The belly cargo advantage of the 77W, airline budget constraints, and supply-chain availability should make WB cabin renovations more common this decade than last. Difficult to project GE90 powered 777s gathering sand.
*regarding b787f: between freighter wingspan issues and a properly sized a359f, the b787f will not leave the drawing board as the 'thin' demand utility will be met by 787 conversions.