In order to make a change here, I would need to see either (a) a good reason to change the established behavior of the teleporter in this situation (as it has the same result, I believe? EDIT: Confirmed, it does have the same result); or (b) a good reason why the portal should differ from the teleporter in this situation.
As it stands - the builder / platformer places a brick in front of himself (not directly under himself), and is a case where a skill is allowed to exist in midair. Therefore, this is the expected outcome when applying consistent physics rules, and any deviation would be introducing a special case. (As always, "it would be a special case" is an argument against it, but not a conclusive one - it can be outweighed if there are strong enough arguments in favor of it.)