My daughter and I like flavors from both Mt. Baker Vapor and Vape Wild.
For us, steep time required (if any) varies from flavor to flavor. Some flavors taste good to us right out of the mailbox, and we vape them as is. Other flavors start "coming into their own" for us any time from a week to several weeks after we get them. It all depends on how you perceive the taste.
When you get your eliquid, try a little. If it tastes good to you, vape it. If you think it still needs "a little something", steep it. Check it every week or so, and when it tastes right to you, vape it. Everything depends on how you perceive the flavor, with the equipment that you are using. The steep times suggested by vendors and customers are based on their taste perception and the equipment they are using when vaping the eliquid. Your taste and equipment may not be the same, and you will have different results. Go by what you like - that is the most important part of the equation.