I'm in the mood to chime in here tonight as I've spent upwards of two hours dealing with Comcast tech support today and getting almost no where. So I understand frustration.
If you make a product that is not up to the tolerances and mechanical design it should be you don't just acknowledge it and say it won't affect performance.
If the user is saying that his screws don't flush mount when they should and are getting chewed up at the track - then that is a serious problem.
You fix the problem and tell the user that you will replace the unit with one that has been manufactured to the right tolerances free of charge.
I fully realize that RC is a destructive hobby and we can't expect things to last long the way they are abused, but if there is something wrong with the product at shipping the replacement is on your dime.
If I spent $100 on a drill that wasn't centered and had a wobbly shaft out of alignment I would return it and expect either a working replacement or my money back, not someone telling me that it will still make a hole in something even if it isn't quite perfectly round. Look at how much $$$ CC has lost on the MMM yet they are still working to make it right. In the growing market for BL conversions I don't think you can afford to be this lax about manufacturing problems - there at least 3 other viable options out there your customer will seek out.
End of vent.