match on all messages in a thread - rather than messages invdividually

[Gaute Hope]

Hi,

I often fail to find threads because there are no messages that match
all the criteria, but the thread combined match the full criterias. 

Often I remember some bits about the whole thread, but they may not be
in any one message - these are hard to find.

Is it possible to search in a way that (through the API) such that the
thread is matching, rather than the individual messages?

How does muted thread work with regard to this? If I have one unmuted
message in a thread that message matches the query. If a new message is
added to a muted thread, is the muted tag applied to it?

Regards, Gaute