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.
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.
The future is turning out to be fascinating as concerning.
I read the entire thing thinking it could cloak a soldier