I've installed one as an emergency tubeless repair then taken it out once back at home and uninflated it back to its original size again so that's definitely doable.
If they have been in a while (months), they do permanently expand. If you take a bit of time to get absolutely all the air out, they do roll up almost as small as when new thought.
Quick size comparison between the RideNow ultralight road inner tubes, Vs normal butyl rubber inner tube.
First impressions (without riding)
So far it's freed up a lot of space in my saddle bag, so, a win in that respect.