A footstep has two basic sounds, the landing, and then the scraping, or release when lifting the foot. Could one cut each footstep sound in half and apply the appropriate ones via some blueprint pipeline? Imagine fx landing your heel on one surface, but the toes overlap to another surface.
And additional sub mix might add effects to change the overall sound based on the soles material and maybe the character’s “personality. Some people have a more stressful way of moving around and make sharper collision noises in real life, others kind of barely make a sound.
The same might be used to mix sounds from collisions, so that if different materials land touch different surfaces, the results would be different, yet not requiring a pre-mixed sound for all situations. Like a procedural collision audio trigger system. It could even go as far as matching debris sound to the size and type of an explosion.
Kind regards.