A solid plinth foot is kinder to a floor than four legs in every way except one: it is a long unbroken edge, and if that edge is bare timber it will scrape a polished floor the first time the chair is dragged rather than lifted. Which, on a dining chair, is every day.
Felt pads stuck on the bottom are the usual answer and they are a poor one. They peel, they collect grit which then does the scratching for them, and they lift the chair by their own thickness so it rocks slightly until they wear down unevenly.
So ours are let in. A shallow recess is routed into the underside of each plinth, running its full length, and the glide sits inside that recess finishing flush with the timber - or a hair below it. Nothing stands proud, so there is nothing to peel and nothing to change the chair's height.
The recess is cut before finishing, so its edges are sealed like every other surface, and it is sized so a replacement glide can be dropped in years later by anyone with a screwdriver. We supply spares with the set.
Nobody turns a dining chair over to look. But a floor with no arcs scratched into it around the table is the visible result.