"Wait until the train has come to a complete stop…" - sounds like a command "Sit! Stand! Wait!..." as if you are talking to a trained dog.

"Please be advised" is a very good expression. It sounds polite, it is non agressive and it carries a good meaning, and generally it is perfect to use in business life.

Now see this examle:

"Please be advised, that your food is on the table ready to be eaten" - It sounds silly if you use this expression to you wife or husbad, don't you think? That is why it is used in "bussiness" not "private" life.

"Please be advice of the save receipt of your letter"

Thank you for reading my comment.