^^^ I use a rolling cushioned mechanics seat/stool. The wheels are large enough that it rolls right over the cracks between the boards. On the lowest setting, I can paint it on in comfort.
A floor sander wouldn't get the rounded edges of the planks.
If this covering lasts 10 years or more (which the last one did) it'll be the last time I will have to do it.
I'll only have 10-12 hrs into the whole job when done. Not that big of a deal for me.