That's actually really cool, thanks!
However, the link don't work from HN for me. For the link to work, users need to click from a trusted domain listed here https://github.com/gorhill/uBlock/blob/bba4732c6b47134c3f54e...
For older versions of uBO, you can already use the old way:
abp:subscribe?location=[...]In my case, the issue is that GitHub doesn't allow the apb|ubo protocol in links. However, no problem, I can use the method with "subscribe.adblockplus.org". Yet, subscribing from contextual menu is a great feature.