Yesterday I noticed an LLNN.com dropping and the NNLL.com available at the time.

Are these desirable?

I can see something random like 79xz.com or 87mz.com being scrutinized for its meaningless selected letters and numbers.

What about sw64.com and 64sw.com-- both now available but nobody picked them up. Is it just in the eye of the beholder? I see 64(bit)s(oft)w(are) which is the future, today. I don't see why a domain like that is overlooked. Many domains have variations of 64 and software in them currently.

If the pattern NNLL/LLNN is researched, and looks like it's being used in longer forms, would it be valuable to anyone else?

They don't interest me, but if they interest you, they're available at the time of this post. Send some DNF if you take them.