David: you appear to be trying to start an open-ended discussion. While your topic is interesting, the StackExchange format is ill-suited to discussions. It's a Q&A site.

Speaking as a contributor to Seasoned Advice, this question would be closed as "opinion-based" there.

(* there is one answer to that question about cold brew, but it's not upvoted and contradicts other answers, so I wanted to ask a question specifically about freezing cold brew)

Well, that's why I'm asking a question on stackexchange.

I'm currently using a 1:5 ratio, which is what the Toddy system recommends. However, I'm not that interested in getting more liquid if that's just dilution; what I'm looking for is ways to maximize the coffee flavor extraction, to the point where I'm maximizing the amount of drinking-strength liquid cold coffee I eventually have.

How much coffee? A little bit (like 1 teaspoon) is normal.