Well here’s my ““research””:
I have never seen this. The first two reset stories didn’t mention this. The infamous amputation story, that utilized reset, didn’t mention this. Mayclore’s reset trilogy didn’t mention this… and I guess the other notable reset story back then is @anon86703525’s Experiment story?
So I am as curious as you are where this idea that fluffies are able to be resetted because of a chip came form. As far as I know, chipped fluffies are mentioned in relation to tracking chip (so that if they went missing and someone found them, the owner can be called/alerted)
EDIT: Oh and of course, the Fuzzy Ponies are chipped. But they are far from normal fluffies.