Tumbleweed
It's not useless because you cant escape in 10seconds that takes to teleport out. You need to do one of those things you mentioned. It also prevents pvp'er hopping around from hot-zone to hot-zone. My point is that feature is useless. The one who's willing to fight will stay anyway, regardless of ability to use teleports. And the one who don't want to fight will escape with ease. Developers would have to implement complete immobility for 10-15 minutes to achieve the goal they intended to get by teleport lock.
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Hello!