Yep, tab management is tricky to get right. We've designed the experience on Insight to make it really easy to close tabs with one tap for exactly this reason (I personally hate it when my browser has a million tabs open), and to bulk close tabs from the tab manager. Safari handles this really nicely as well, I think we have some room for improvement. I like the idea of not persisting search sessions, that would be interesting to explore on iOS. Thanks for the feedback!