I don't think it's a good idea to require the body to be immobile/in a state of sleep becsuse that puts a hard limit on how long you can use it for(bed sores that coma patients have to deal with and sleep cycles being disrupted) unless we make further more difficult breakthroughs.

We could make something similar to full dive with today's tech with neural ankle and wrist interfaces where an artificial set of virtual limbs are created. So kind of like an octopus except you're not moving your real limbs. And a high fov display for your eyes.

All of this would not require a brainchip.