It’s easiest to see what’s going on if you turn on the background of the label and change its background colour to something different than the window.
When you change the rotation of the text to 270°, the text will only be where you think it should be when the bounding box of the label is square. Knowing this, it is possible to get this to work if you’re careful:
- Temporarily increase the width of your template.
- Create a square label big enough to hold the longest string. Position it with the mouse at the correct height and against the left-hand edge of the template.
- Change the position of the left-hand of the label using P to a negative value until it is where you want it.
- Reduce the width of the template.
Once you’ve done this you mustn’t move the label with your mouse or it will move until its left-hand edge is at the left-hand of the template. It would probably be best to lock it in position.
Hopefully this workaround will help you get the layout you want.