Not sure what your aim is, but the coinbase NYA voting is just expressing a position right now. The true signalling come next month when SegWit2x code is fully tested.
"Fully tested" in about as much time as it would take to test some tiny little bug fixes.
It's fine. Signalling that they will signal is good enough for now - I see it as unlikely that they'll look at the proposal, which they know about anyway, and say "nah, line 637 is a poor line of code, we can't support this now".