Foffa Bikes

1. A good headset properly installed won't need to be adjusted often, whether it's AHead or threaded. I have a Tange Levin Alloy on my hack bike which was installed at the Kuwahara factory in Japan 28 years ago, and it hasn't been touched by a spanner since. The C-Record installed by Brian Rourke on my Lo-Pro has only done 20 years without attention so far, so the jury is out on that one :-) If you're having to adjust the headsets on your builds, it's only because they are shit components installed badly.
   
2. If that were true, BSOs would have threadless headsets. They don't.
   
3. Not really true, since a 50mm stack of spacers and a 100mm×17° flip flop stem will give a 104mm adjustment range, with just 8mm in the middle which can't be achieved at the crossover. Of course, it's easy and cheap (for you) to replace the stem with a different length and angle to widen the range of possible fit points, and I'm sure you already offer this service even with your cheap and nasty quill stems at no cost to the customer, since you are a bespoke supplier.
   

And here endeth the lesson.

Many thanks Tester.