Over the last couple of weeks I have spent a ton of time learning OnShape. I came from a 3d art/animation background, so going from freeform to parametric, measurement and constraint drive modeling was a tough transition at first. Now I’m absolutely loving it. I can use a single dimension with constraints to drive a model from the ground up. Making an alteration is as simple as changing a dimension.
As far as export to Glowforge, you can already export sketch profiles to DWG so importing into Illustrator (I don’t know if GF currently supports DWG?) is a snap. There are also already integrations with third party apps that can add additional functionality, and featurescript allows you to program new features right into the app.
Yeesh, I sound like their sales staff must! I promise I’m not. If you haven’t checked it out, it’s free up to 100mb of private documents (and 5gb of public documents) and their tutorials and documentation are fantastic. I went from spending hours honing a 3d design in lightwave to a few minutes of modeling and dimensioning to build the same part (on my iPad by the way) in OnShape. It’s a bit of a steep learning curve at first, especially if the concepts are foreign, but once you get over the hump it’s well worth the time you’ll invest.