Is there a way to call that directly from Sketchup?

@macumber, slow your roll!

You can open the Ruby console and type this bad boy:

OpenStudio::Plugin.model_manager.model_interface.openstudio_model.getSurfaces.each {|s| s.setVertices(OpenStudio::removeCollinear(s.vertices))}

Hopefully that will not crash SketchUp :-) And to be clear it would be much better to do that in a measure ;-)

Thanks! Could you explain briefly would it be so much better in a measure? I'm new to OS, so my natural instinct would be to remove mistakes once and for all and not have to do it each time (though I'm starting to think that those types of problems just arise out of nowhere)

If you use the Apply Measures Now function in the OpenStudio Application it will remove the errors once and for all. Putting your code in a measure requires a bit more overhead (just dealing with all the boiler plate stuff) but it will make it easier to run using the application, PAT, Analysis Spreadsheet on any model you want. Plus running code directly in the Ruby console is likely to crash the plug-in, I don't generally recommend it, measures are more repeatable and running in the application won't cause bad interactions with SketchUp.