Constrain Paintbrush (Affinity Photo) needs to detect direction more quickly/precisely

[MaybeSo]

When constraining the paintbrush stroke (holding down the Shift key), Affinity Photo needs to detect the direction of travel after only 1 pixel of movement.  I don't know how much of a sample it takes to determine the direction of movement, but it doesn't detect/kick-in/constrain fast enough.  Many times I will start the brush stroke moving, press the Shift key, and Affinity Photo takes that as a cue to draw a line from the last known point ... (best case) I wind up with an unintentional, usually diagonal, line through my work that I have to Undo ... worst case I don't detect it because the line has struck through an area of the screen that is now out of view.

I use a mouse to clean up a lot of old rasterized text, continuously zooming in and out, often with very small brush sizes, so I rely on constrain for much of my work ... I think I must have continuous 10-15% rework all day because of this.