If you press A to dismount 1 frame after letting go of R, Link will dismount Epona while still moving and slide on the ground for a moment before gaining control again. This can be used to cross voids as Epona won't fall during the dismount animation, or can be combined with a brakeslide to achieve high movement speeds.
If you start an Epona slide while still on land, and then cross over a void, Epona won't fall while Link dismounts. Holding forward on the control stick will make Link hop forward so you can grab the ledge