Shove should be a bonus action for Fighters and Barbarians only, and a full action for every other class.
Shoving should be a bonus action for specific features (like Open Hand Monk) or feats (Shield Master), expecially if they want to introduce the option to toggle between shove away and shove prone. Shove prone as bonus for every is just a cheat
Or we could separate shove and keep it bonus for everyone from a full action Knockout (to be influeced by the likes avobe).
We can all agree btw that base shove distance of 15ft is too much. Makes some class features like Battlemaster pushing attack (15ft) or Repelling blast much less useful: shoving area is already conviniently covered, why bother taking options like these instead of something else