Moving message preview to second line in single line view?

Okay, I understand the inherent issue with asking for a “second” line in “single” line mode.

However I find the compact view generally cluttered, and prefer the neat and orderly nature of having everything aligned in fixed columns. Other than the preview, that is, because I just can’t get enough of a preview from a column. However moving the preview to below all the other columns, perhaps in a slightly smaller or greyish color, would solve that.

But despite tons of customizations, I can’t seem to make this happen. Am I just missing something simple?

I would suggest to do a dummy mockup of what you propose for your feature request.