Some bad news and some good news. The bad news is that you may have noticed that temperature sometimes affects the scale readings. In some cases this can be fairly significant -- up to about 5 kg. You'll know it when you see it because it appears as a daily cycle of weight as shown in the graph to the right. This doesn't happen to every scale, so if you haven't noticed, then don't worry.
The good news is that we're doing something about it.
We've spent months now running temperature tests of various kinds in a commercial environmental chamber. It has been difficult to isolate the root cause of the issue, but we've worked out that it's not the electronics nor the loadcells. Part of the problem is that we can't always reproduce the problem: it doesn't happen on every scale and it doesn't happen all the time.
We've finally concluded that the main problem appears to be the mounting of the loadcells. The wooden mount expands at a different rate than the metal loadcell, and if the loadcell is mounted too tight against the wood, any movement registers as weight.