sky light 4.18

Hi guys. there is any connection between num indirect Lighting bounces and Num Sky Lighting Bounces? i mean when you pute Num indirect Lighting Bounces to 0 skylight multi bounces will work?
its seems when you pute num indirect Lighting bounces to 0 skylight bounces will stop to working .( i mean when skylight is your only light source )
and i want to know there is a connection between roughness object and bounces? i mean an object with specular to 1 and roughness to 0 will have more bounces light?! ( i test it and its seems roughness of objects is not effect to bounces )