Good job and good summary!
The http://gmic.eu website could benefit from more of the examples and tutorials found on https://pixls.us/ and https://discuss.pixls.us, or at least provide the appropriate links. Maybe the site just needs an overhaul; e.g., we have pages that still say “Latest stable version: 1.7.4” and have old tutorials that might need revising. That kind of gives G’MIC less credit than it deserves.