Allow more than one line of text visible when auto collapsing posts

[Jolly-Friend-9876]

Pitch

When specifying how long "long text" is for the purposes of auto collapsing posts, you can specify how many pixels is too long. I'd like to specify, either in number of pixels or number of lines, how many lines of text to make visible when a post is auto collapsed.

Motivation

For me, one line of text is not enough to know whether I want to see the whole thing. I expect I am not in the minority. Also, you already have some logic in code for the number of pixels for long text, so it might be extendable to the above request.