A short look at Design and Punishment in Mario Maker 2 | Boogs 

I kinda get your complain but there's a simple solution to the first example: use the "you can't get hit once" clear condition. That way the player knows he has to get a damageless run to finish right-away, before starting to play, even! It's not perfect as it prevents you from using checkpoints, but these types of levels foccused on very specific mechanics tied to powerups tend to work better in short formats, I find.