I posted some details about how one might go about doing this awhile ago here: Input Action And Axis Mappings - Announcements - Epic Developer Community Forums
I don’t currently have plans to provide any built in system for key remapping as I feel it is very much a UI problem more than the function calls and each game will want to do things differently. I like to imagine that we’ll eventually see community plugins with some kind of standard menu set that might include key remapping.