In bug 1504254, the implementation of double click to edit or switch a preference is removing the ability of using triple click to select a preference name or value accurately.

However, Filip Š has demonstrated that it's possible to keep the triple click interaction by adding a timeout to the double click processing, and the resulting user experience works well. This solution, however, adds a little code complexity due to the processing being asynchronous.

I'm not sure of how prevalent the use of triple click is, compared to drag to select, and it may turn out that it's not really necessary and this bug will be WONTFIX. Alternatively, a different interaction for the same use case could be devised.

For the preference value, the double click followed by CTRL+C (or other context menu options) already covers the use case.

I'm not sure of how prevalent the use of triple click is

FWIW, for me this is the one advantage of the new about:config compared to the old one. The triple click followed by CMD+C to copy a preference name or value is much faster than using a contextmenu and also faster than drag to select + CMD+C.

Hii! I want to work on this issue. Can you please assign me this? Also, Can I get some idea about how to proceed?