>>274164281
you do, honestly. Vive trackers only ever have 4 visible and tracking at most times. Since it's smaller, you can have it occlude ironically less sometimes, because there's less surface to get in the way, you can do things like have it stick out a lot more without being awkward. 
remember that the tracker needs to be "in space" relative to your avatar the same distance to be accurate. So, if your tracker balls are 4 inches from the top of your foot, then that's where you should bind in. This is why using playspace mover on long legged avatars works.
So a hive tracker could be above the foot on a stick and still work, making it less likely to be occluded by the other foot, since it weighs almost nothing. 
you could have one up high and one low so they never get in each other's way. Or, since they're so cheap, you could do elbow, chest, waist, knee, foot, hand and head tracking for the cost of 6 point tracking, so IK is basically perfect.