Since you matched the FOV's in CSGO and Rainbow Six Siege, you can convert your hipfire sensitivity from CSGO using 360 distance which you have done correctly. As for your scopes, you're using "0.818933027098955175" zoom sensitivity in CSGO which is identical to converting using monitor distance matched at 0%. However, because Siege doesn't have separate ADS sliders for iron sight and ACOG, you have to pick between the two for an accurate calculation.