I hope this isn't some exploit or cheat or SOMEONE is gonna be dissapointed. During a long crossfire match on Grenade III, I engaged in a fight with a tank. He shoots a PG which successfully hits me. I dive back into cover and I notice I have enough money to upgrade a skill. As soon as I upgrade, the stickerz are gone. How long are stickerz suppose to blind anyway, 4-5 seconds? I upgraded in less than two. I'm not sure if that was a glitch or anything at all, but if you can remove the stickerz by just upgrading, I smell a future exploit and patch.
If this does happen, its not that game breaking. It takes about the same time as a "clutch passive" upgrade for a tank or support which gives the class full health, and is very risky to do.
Honestly it seems like a legit strategy to me, I mean Tanks do it something similar all the time for health boosts.