Honestly, I don't really follow any teaser contents and just wait for the songs to drop so I don't really know how long each company teaser promotion lasts. Yet, I start to feel it very long with groups under Jyp more than other company that I follow or big 4. I set my eyes on Nmixx and Twice cb recently and this is kinda bother me how long it took for all these teaser before they drop the songs. I might totally wrong in this, but this is just what I feel about their teaser promotion period.
Overall, I feel like kpop group's teaser release period lasts longer than their actual promotion period after the cb. Again, I might wrong 🤷🏻♀️