Partial least squares (PLS)
Well, I have a python/numpy PLS implementation that I could probably
  adapt into a python script block, but is this necessary? Please tell
  me that it's just a mouse-click/import away.


Welcome to the site! I wish I could tell you that what you want is a simple point-and-click but I don't think that it will be. 

Generally speaking, most people use Orange as a tool for the visualization layer while you are looking for a tool for your modeling layer. Python has tons and tons of tools that you can use for modeling and should fit what you need. So, while that will be more steps for you, it will ultimately provide you more flexibility for other projects you may do in the future; just use Orange for the visualizations.