On the 70D, disabling auto power-off does not necessarily stop Live View from timing out. Based on the shared workaround, the practical way to keep Live View active is to simulate a half-press of the shutter the whole time.

In Magic Lantern, a feature called “sticky half-shutter” can do this on some cameras, but the answer notes that the available 70D build does not include that option. Their workaround was to physically hold the shutter button at the half-press point, which kept Live View active for streaming.

So the short answer is: there does not appear to be a normal camera setting that fully disables the 70D’s Live View timeout, and on that ML version the workaround is maintaining half-shutter input.