I think I found a nice replacement for Context Search (the one by Ben Basson) and Drag & Drop Zones (which is broken).

It's a very good thing to be able to import engines from the search.json file.

Some of my engines were imported twice, because of the multiple links that exist in some files, but I must clarify that I created custom search engines with XML files, in an amateur way (imitating other search engines) and maybe I didn't do too well. Edit : it is now fixed.

The open as link button doesn't work but I expect it will be fixed soon enough. Edit : it actually worked for single-word and hyphened-word searches but not for a text with spaces or words separated by colons. The dev allowed the former with their last update but the later is forbidden by Mozilla.

Would it be possible to save the preferences ?

Thanks for your work, it is well thought out and deserves a better place on this website.