The plan is to flight-test a small-diameter fuel hose up to 120 feet in length by the end of the year, extending it from the standard 80-90 feet. A longer hose is needed to allow helicopter pilots to see the tailplane during the fuel transfer and cut the turbulence of flying behind the four powerful TP-400 turboprop engines from Europrop International.
There are two problems with the small diameter hose. #1 is fuel flow. Can they get the necessary/desired fuel flow thru the hose, or will customers have to accept slower and therefore longer aerial refueling. #2 is rigidity. The smaller diameter hose will be significantly more flexible. Will the basket be stable farther back AND flying at the end of a much more flexible hose. The smaller diameter hose is required to fit the hose onto the existing hose reel and into the existing refuel pod. Staying with the current diameter hose but extending its length will require significant redesign to both, adding time and cost.
There is a modification of installing a small step to allow 116 paratroopers to jump from both sides of the fuselage, with 58 from each side door. A full test jump of 116 troops is due by the end of the year. These would be alternate jumps, with work ongoing to enable a simultaneous jump from both doors.
C-17 explored a similar option. The US Army and USAF were adamantly opposed to any system that imposed/ensured alternating jumps from the left and right troop doors. They were firm in their requirement that a solution be found to enable simultaneous jumps from both doors. I'm pretty sure that the C-17 solution would work for A400M.