I’m wondering, is there a way to make a column along the left or right hand side of the screen with health and magic and stuff on it that is updated every turn, without using Flexible windows?
Not quite what you’re asking, I know, but you can always re-purpose the status bar.
Which, I understand, isn’t displayed in Parchment for some games, so it’s not ideal if you want online play.
I did try the status bar, but it doesn’t seem to print everything I put in it, and I’m not really happy about having it all squashed up there.
There’s an extension - Basic Screen Effects, maybe? - that allows you a multi-line status bar. But, if you don’t like it, that’s not relevant. 
I could be wrong, but I can’t see a way to do what you want without Flexible Windows.
You could implement it yourself using I6 code just as Flexible Windows does. But I can’t see any advantages to do that rather than using the extension, it’s just more work for you!