From what I understand, the reason trackers knife was removed from eh game was because the vision it gave players too much information and let them avoid death leading to longer and less eventful games. The patch trackers knife was removed on was also joked to be the patch that Lee Sin was killed since he relied on trackers knife a lot for mobility. I feel like a jungle item could be added that would let you place something you could hop to just like a ward but didn't give you any vision, this would remove the trade off of vision for mobility or the other way around some champions like Lee Sin or Jax could benefit from. I know there's the Ingenious Hunter rune that you can take to reduce the cool down of trinkets which would let you ward hop more often, but other champions don't need to make this trade off because they aren't reliant on wards for their dashes. Introducing a jungle item like this could allow these champions to have mobility without trading off vision, they would still have to choose to opt for this item rather than getting chilling or challenging smite but that seems like a more reasonable trade-off than sacrificing mobility and possible impact in the game that comes from it in my opinion