Feature summary (what you would like to be able to do and where):
Make it possible to embed gadget options in other panes of Special:Preferences than the gadgets pane. This would be a setting in the gadgets definition page for the wiki. This task does not propose to be able to list a gadget under multiple panes, just a single pane other than Gadgets.

Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
Gadgets are poorly integrated with the rest of the preference tabs. The pane specific to gadgets turns quickly into a hopefully organized but usually fairly flat list of gadgets that are easy to get lost in (humans like to think hierarchically). The headings on that pane often duplicate the other panes in special:preferences.

Benefits (why should this be implemented?):
Discoverability of gadgets improves and we stop duplicating the other panes, which leads to better use of that specific gadgets pane as "it doesn't fit elsewhere" or possibly even "here are some ones with different groupings than provided in other preference panes".

Why this may be should not be implemented:
Gadgets are community-created rather than scrutinized via code review etc. etc. which may (but hopefully don't) carry with them associated security risks, etc. etc., which may not be the implications carried on the currently non-gadget panes. I think this can be overcome with the usual disclaimer and some sort of section heading on the specific panes e.g. "Gadgets"