I know this isn't the way it works now but:

My preferences:

First search results are only where the match is in the title (i.e., come before any results where the only match is in the body), and of those, in reverse chronological order.

An example where I see improvement needed. Search for: fiatjaf

Why would a post from half a year ago come before one from yesterday? How could that one have been deemed to be more relevant?

Exact search:

Matches for exact search (in quotes) would come before any that are relevant that do not have that exact phrase.

Example: "private key"

Why would a comment reply that has only "256 bit key" come before some other comment reply that has an exact match, "private key"?

I'm assuming this is because exact search isn't supported and my search is eseentially identical whether I used quotes (phrase) versus just searched on the two words.

Search of URL or domain:

I want to search on a specific URL, or maybe just a domain and see all Link Posts for that URL or domain, in reverse chronological order).

Example: bitcoinmagazine.com

I want to see the most recent Link posts that are for a link to bitcoinmagazine.com

of course, if I provided a specific URL, I am looking for just that URL (or at least, any URL that include that.

Example: reddit.com/r/bitcoin

Only include in the search results matches from r/bitcoin (which also includes other subdomain prefixes, such as old.reddit.com/r/bitcoin/xxxxxxx )

Oh, and after Link posts, the next set of results should be Description posts where that URL or domain matched in the description. In other words, posts come ahead of comments/replies, but of posts, Link posts with a match come before Description posts with a match.

After that, by relevance is fine. But maybe eventually add a drop down or something where I can request sort "by most recent" or whatever label reverse chronological is given.