The only things that bug me are
1) How did I miss seeing that setting?
2) How did my online searches ask the wrong question as I couldn't find that anywhere?
I guess it's a sign that old age/senility is setting in
1. Like xABD says, it's not the most user friendly program around, so easy to miss things; and the row height adjustment seems to be a real issue with a bucketload of folks, so you were in good company.
2. I've learned from Paddy that it's all about the way you search. I took a stab with "calibre 2 row height vs calibre 1 row height", and happened to hit it just right. Otherwise, you'd have been waiting for Paddy to find this info as she's the queen of searching.
Old age? HA! You're YOUNG, have no fears.