The game will warn you when you are about to reach the point of no return, so there's no need to worry about being locked out of side quests from progressing the Main Quest. Besides Oils, you can make many other useful consumables through Alchemy in The Witcher 3, such https://bookmarkplaces.com/story20036161/top-mais-recente-cinco-the-witcher-3-wild-hunt-not%C3%ADcias-urban