The default behaviour for the arrows on the quantity field is to increment by 0.01. Support has informed me this is by design to accommodate orders that require fractional quantities. In my previous experience, the arrows used to increment by 1, and I argue this should still be the default behaviour, especially given I have checked with the staff member responsible for processing purchase orders here, and she was not even aware that the quantity field allowed fractional input.

I understand this is a small issue in the grand scheme of things, but it gives the impression Compass do not engage with actual users in their UX design process.