A great alternative to the Ultimate Screen Teleporter. The usage might be a bit weird since you still have to place the blocks inside the playable area and not outside. In other words: You'd place these blocks in the same way as you'd do with their regular equilivants.
I also have fixed the position checking at the edge of vertical levels where you just have to touch the screen edge instead to really go offscreen.
Finally, I would recommend on creating a routine and use a flag (like the carry flag) to determine whether to run the code or not.