Cool! I like that trick of scanning along the horizontal / vertical when you have a rough idea of where a mark will be.
Feels like it makes a lot of things possible in Realtalk that we would need a shader to do globally in a responsive-enough way.
I wonder if a stopgap for making `Here` more usable would be to highlight the current code editor line / code editor cursor position on the page itself (wherever it would print).
I feel like I've suggested things like this before (current line, possibly current scrolled viewport), maybe played around with it also.
It's interesting that the trace printing and the live box detection are apparently completely independent systems -- one uses the general tracing stuff, the other uses your new custom line-following-to-find-boxes stuff.