Proposed change to Teemo

I was going over ways to balance several champions that seem to have a lot of power in solo queue and the most glaring problem to me with the vision changes in S4 (besides Evelynn, who got nerfed with her E change) was Teemo and his Ultimate. As we all know, his Noxious traps are invisible until detonate or Swept/Pink warded. Now, as we all know, Evelynn used to have a stealth that would last until she attacked or it ended in duration, regardless of whether she was right next to an enemy champion or not. This was deemed anti-fun and changed with her rework, which involved perma-stealth until she was within vision range of a champion/attacked. While she was still considered imbalanced, she still was a bit more balanced than appearing out of stealth and stunning/melting someone despite the fact that she was right next to her opponents.

I propose we do the same thing to Teemo's shrooms. Give them invisibility until seen by an enemy champion (obviously the vision range has to be short, around 100-200 units away from the detonation range) so that the champion has a chance to avoid/dodge or the choice to willingly walk over it. The change still gives Teemo map control/zone control while giving opponents the ability to counterplay (sidestep it unless there's an entire wall). In addition, it helps in chases (be they either way) as it forces the enemy to back off from the chase/deviate from their escape path while still making it fair since the champions can see and willingly make the choice. They would still untargetable until swept with a trinket/pink warded/true vision (but I would not be above giving melee champions the ability to clear the shrooms in 3-5 hits without a sweeper/pink ward/true vision, whereas ranged champions have no ability/have to be almost detonating it in order to destroy it)