Thanks Dennis !
This is a very cool plugin. I can see a use for me for aligning vertices along a diagonal ...
Just FYI I've made a stupid test and here's the result (the box conform object is at right) :
On the above picture, you end up with something somewhere that you can't even unselect by clicking on the workspace ...
After some "undo" to restore the initial state of the block object, I've rotated it on 45 degres on the Y axis,
selected all the block object and performed the box conform process (to see how it deals with faces non facing any axis), worked very well.
Then after some "undo" again to restore the initial state of the block object, I've re-selected the right vertices as in the first picture, and re-performed the plugin :
As stated, this is just FYI, because yes ... this is a stupid way of using your plugin