I've updated the plugin to be a bit more powerful. I believe the issue you were having with alignment is that the plugin was intended for aligning things like equal signs in the middle of lines, do it always inserted spaces. The way that sublime measures columns of characters, only a single space would have been inserted if you use tabs for indenting.
That said, I've updated the plugin to do what I think you were intending to do, which is to align the left edge of each line to the same indent level. If you have a multi-line selection, the plugin will cause all lines to be indented to the same level. As a bonus, if you run it a second time, the first set of equal signs with be aligned using spaces.
The original functionality for multiple selections still exists and functions that same way.
If any of what I described is confusing, please see the readme for examples.