There is no command for hitting the ground and coming back to a starting position but enemy should stop moving if it has solid behavior and touches the ground. Also, you can set a time when to call another command.

I believe that with a timeline something like Thwomp can be made with several timings and commands.
Also, thank you!

It's nice to know that somebody thinks about me when I am going to be away for more amount of time and it's nice to talk to you too again.

It is not necessary, however, to worry too much. I simply have too little free time.