I've read hundreds, maybe thousands, of comments on Linear vs Threaded view and 99.999999% of them say they hate threaded view and there is no use for it. Some of the coders who work for the most popular software companies have written that they will never offer a fully threaded view since there is zero demand for it.
Also - most people today have no idea what fully threaded view is - it's been so long since it was offered few have ever seen it or remember it.
BUT... checking out various forums there are very very few that have discussions the way we do on this forum. The back and forth, the many replies within one topic but to a specific poster.
When I did what you did, request fully threaded, I invariably got the reply that using the 'quote' feature (that's on this software as well), replaces fully threaded view. It doesn't. Anyone who has ever been on a Linear forum with 'quotes' can easily see it's nothing like fully threaded view. - JamesJM