Currently, a player is able to launch another player with a structure (commonly a cube) and then launch that structure up by spawning another structure under that one, repeatedly hitting the launched player when structures from beneath them. There are minimal counters to this that do not require a shift stone such as flow or (purportly) guard to escape, or stubborn to negate if the player is dashing or jumping. This may or may not be an issue, but AFAIK many players dislike it and feel it is a cheap move.

I think one way to solve this situation might be to have the structure that impacts the player from beneath still launch that player, but also break from impact with them. Hopefully by the time the player who launched the other player might try to follow-up with more structure launches, the midair player may be able to start falling, possibly allowing for iron boots to break a follow-up structure launch.