I'm only about 100 days behind! Not bad!
Apparently, noone else has answered this one nor posted again about ETTR, so I'll give it a shot.
2nd - the addition of 2 more "bits" to the 1d3 raw files adds significantly to the space available to adjust shadows. At some point increased bit depth should make ETTR largely unnecessary. At 14 are we there?
I don't see how all the bits in the world will make it unnecessary to follow the ETTR doctrine. If a highlight is blown, it's blown because you've over-exposed beyond the sensor's limits.
What a higher bit depth can give you, however, is the headroom to encode a higher dynamic range, or the same dynamic range with smoother gradients.
Ideally speaking, though, you wouldn't have a bit depth at all.