Summary
One thing I miss from Affinity Photo/ Designer is its pixel precise colour picker/selector/sampler. It is basically a magnifying glass that you may be familiar with in iOS when dragging the cursor in a piece of text. Because of the magnifier, it is very clear which pixel is selected to extract a colour value from.
Problem
Currently, it is difficult to select a colour precisely when it occupies a small portion of the canvas. This requires zooming in and a bit of trial and error. So you may end up sampling a colour a couple of times. This takes additional time.
Solution
Add a magnification widget alongside the colour sampler. That way, the precise pixel values are shown. This is also relevant for the palette, because you can add swatches with a high level of precision.