Is there any way that we can make it so horses get their own footstep sounds as well, cause it sounds weird when the vanilla galloping mixes with the PF footsteps so I felt it would be better if horses were able to get their own SFX for galloping on certain terrain just like how players get it.

The mod can already do this. Go into the settings and make sure you set the target to all entities and turned on exclusive mode to disable mob's regular footsteps.