Mynatt analyzed whiteboard use in 1999's "The Writing on the Wall" [1], which led to an interactive whiteboard system called Flatland [2], but it's not focused on programming.

More recent, detailed, and programming-specific is "How Software Designers Interact with Sketches at the Whiteboard" [3].

I had thought I remembered a site with a more thorough treatment of this, but I might have just been thinking of the sprawling Visual Programming Codex: https://github.com/ivanreese/visual-programming-codex

[1] http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.13.... (PDF)

[2] https://ecl.cc.gatech.edu/sites/default/files/publications/C... (PDF)

[3] https://cs.gmu.edu/~tlatoza/papers/tse15-sketching.pdf (PDF)