MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
Sounds a bit dramatic, but sad to hear that isn't working out for you. Are you using a standard grip for your dominant hand? You should be able to hold the stock at all times with it. Personally I would recommend adding a sling (or a guitar strap, rope, etc.) to your stock so you can let it fall while you use your hands for something else (such as switching to a secondary weapon). I have no estimate for the magnetic grips as I'm still testing out the best possible design among a few, but should be a couple of months.