Now it should be possible to make changes to your input settings while in multiplayer 
and some other improvements:
Today we’ll release DCS 1.5.4 to Open Beta for open testing.
DCS World•Multiplayer. New integrity check system*
•Multiplayer. New extrapolation algorithm
•Multiplayer. Added an input adjustment possibility
•New and improved MiG-29 model
•New Campaign Builder design with multi language support
•ME. Payload panel. Added skin preview in the 3D view
•ME. Added new trigger UNIT’S ARGUMENT IN RANGE for checking animation argument for any 3D model in mission
•ME. Added new trigger PLAYER’S UNIT ARGUMENT IN RANGE for checking animation arguments for player’s 3D model of unit in mission
•ME. The year can now be changed on the briefing menu
•ME. Season is now automatic and dependent on the date of the mission
•Fixed Object.destroy() for cargo objects
•Fixed Unit.getRadar() to return correct information for ground units with radars
•Fixed AI issues caused by toggling AI on/off
•Fixed dynamically added ground units now correctly follow orders
•ME. Added the ability to place helicopters on the ground for the cold and hot start
•Encyclopedia. New 3D view
•Options panel. New design
•Support of hot plug of input devices now
•Module manager. Added DRM button for activation/deactivation
•Returned moon in the sky
•Corrected animation of airshow cone
•Oculus Rift. RadioCommunications and triggered messages menu font increased
•Oculus Rift. Kneeboard and terrain clipping issues fixed
•Oculus Rift. Oculus Zoom action added to “UI layer” input options
•Oculus Rift. VR settings can now be applied without restarting GUI