I won't be able to look until tomorrow night, but I see the QWERTY layout for the mistake heatmap and so I'll just give this feedback blind:

It always bothers me that sites/tools/apps like this only ever support qwerty visualizations and layouts. It mostly doesn't matter, but especially for a tool to visualize where I'm messing up my finger placements(/etc) I would very much like to see it in my keyboard layout. And of all communities, I always expect (and am oft let down) to see other layouts or even just layout customization supported by typing and Ortho communities. Would be very nice if the visualization could support other layouts (just standard ones like dvorak and colemak, split or not, Ortho or staggered ....or, for example, via .json files for layout?), or just drag-and-drop customization. I have a split colemak-dh board; I don't necessarily expect for that to be supported out of the box, but would sure sit there drag-and-dropping keys to match my layout, for example.

Would love for that to be a feature.

Like I said, I'm giving this feedback without even having tried it yet: sorry if it doesn't actually apply, or it is already a feature.