I’ve worked on this for my game - spherical voxel type game. What I found is that yaw becomes a relative only property. What I did was implement stuff derived at the Pawn level. I made a very cut down version of the character movement class, however I do support stepping, being floor aware, sliding, jumping, sending updates to the server and root animation. It is quite funny run jumping on a spherical work - thinking escape velocity.
Of course there is a performance penalty - basically needing to translate things between gravity relative and work relative co-ordinates.
It will be great when unreal supports it. I’m sure I have heaps of corner cases that have bugs.