So text characters have a stroke outline and a fill. The problem is that the stroke just follows the outline of a character. I want to be able to just use the fill as though it were a stroke and be able to vary its width and other properties. When I vary stroke width, it just changes the outline width.
Can I convert text somehow so the inside becomes a curve, or do I have to trace it?

Maybe this:

Thanks, I've found these forum discussions too which are related.
https://inkscape.org/forums/beyond/object-to-path-centerline-detection/

https://inkscape.org/forums/questions/is-there-a-path-to-stroke-function/

I've discovered that using "Linked offset" sort of does what I want.