>>357428763
If you don't play vrc than there are almost no games that use fbt ATM. but as far as im aware FBT tech isnt going to change much in the next couple of years(maybe). But it will do just about the same thing as the stuff now. So atm you shouldn't get fbt but I disagree with your time scale of 7 years. I think its more like 1 or 2. 
>>357429413
I posted two of them. one uses manual redirected walking to climb stairs, the other is breaching a door by kicking it. Having your body interact with the world to go up stairs is only a small part of what I imagine it can do. This would allow extreme amounts of freedom of motion to say clamber over a wall or step into a car to drive. My system is not where I want it to be. It needs to be more like gorilla tag but with your feet. Having intractable things with your body, like the feet and the door, will help raise immersion. A better tracked chest will help with having useful inventories. These are the easier ones. A system that I've thought about is trying to get the user to 'play' dead. How would you incentivize the user to say get on the ground because they've been injured(ingame)? One way is I've thought is to have the player match their body in the game. so they would go into a third person for a second or some other solution somehow, and see that they needed to get lower to match or get close to it then they would have better control of the body. Not sure if this one would work yet. Other than that there are more subtly things that we use our lower body for that would be nice to have in VR. Something like pushing a drawer with your waist, or maybe using stance to calculation recoil on weapons. Thats all without even having feedback. Which could be an easy addition to even fbt now. but no one is making such a thing.