FYI Ukraine already has FLIR invisibility cloaks (fancy camo space blankets): https://www.youtube.com/watch?v=GfdF3iIwoX4
This is thermal cloak, explained here: https://www.youtube.com/watch?v=CM2RJi4mRZ0&t=52s
Notably it only works after the heat flow settles back down to equilibrium. If you're moving, it doesn't work.
The videos remind me of the scene in Dune where Paul is hiding from the hunter-seeker that tracks based on movement.
If you're in free space, the surface can't shine its IR differently in different directions, so under FLIR it will just look like the average ambient temperature. This is no better than existing (cheap and light) space blanket camo systems.