From @philsward in https://github.com/backdrop/backdrop-issues/issues/4829#issuecomment-781...
Also, both Themes and Modules need a "remove/delete" option to completely delete them from the file system. Once a theme or module is installed through the GUI, there is no way to get rid of it from the GUI.
GitHub Issue #:
5320
Recent comments
There is also Node Comments Search - this searches the node and all comments (default search is node and first page of comments) as part of the content search. Izzy's module above is a separate...
Search does not include comments
I have created a new module comment_search
Search does not include comments
If there is no response, alternatively, you can use a View with a list of comments, with a filter based on the comment text. I haven't tried it myself, I just got an idea.
Search does not include comments