What's gentler on screw heads: a regular screwdriver/drill, or an impact?
That’s funny , sorry but force is needed to break the screw loose , an impact if at the wrong angle will cause problems as a hand held driver will. If there is paint both will damage the paint. But a t45 is large and if the bit is fully inserted and perpendicular there is really no difference as an impact only hits hard enough to get the screw moving. Once the breaking force to remove the screw is achieved there is no real difference except the impact will be faster.