In terms of disguising synthetic aperture radar that’s much harder with a satellite which needs to send out a strong signal to hit stuff at 300+ miles and then bounce back to another detector at 300+ miles. Especially when there is such a limited number of easily tracked satellites to be concerned with.

10x distance requires 100x the signal.

When it comes to being stealthy from above, jets bank to turn. Pilots can handle much higher g loads vertically than horizontally.