Heatmaps are not journeys
A heatmap answers a spatial question: where did attention linger on this screen? A journey map answers a sequential question: which decisions were available, and in what order did people take them? Collapsing the two is how squads ship a warmer button and call it cartography.
We still look at heatmaps. They are useful for spotting dead zones on a form. They cannot tell you whether a tap changed the next option. They cannot tell you that “complete later” was a silent exit. They cannot survive a PM who asks what happened after the screen.
Colour is not evidence of a step
Hot spots often sit on decorative chrome: a mascot, a progress bar, a legal footnote people tap by accident. If you promote those regions into funnel steps, your User Journey Mapping for Apps work becomes interior decoration. In studio critiques we pin the heatmap beside the paper spine and ask which marks correspond to named decisions. Most of the heat does not make the cut.
Use them as sketches
Bring a heatmap to week one of Path Cartography Studio as a sketch, the way you might bring a screenshot. Leave it off the deliverable atlas unless a spatial problem is the actual brief. If your only artefact is a coloured screen, you have not mapped a journey. You have photographed a surface.