Can you please clarify what the situation is? Which files are you installing? The new hatch extension for EggBot should appear as “Hatch Fill…” in the EggBot extensions menu, not the EggBot Contributed extensions menu. (Note also that you should install the latest version of plotink: https://github.com/evil-mad/plotink )
If you have replaced both eggbot_hatch.inx and eggbot_hatch.py, and have installed the files from plotink, and your menu is not updating after you restart Inkscape, then either (1) you have not copied and/or replaced the correct files or (2) you’re launching a second copy of Inkscape.
Separately, I’m not sure what USB diagnostics you are referring to– the Hatch Fill extension does not use any USB connectivity, diagnostic or otherwise.
