I say "yes please"! The only comment I have - why not +trace to make it "compatible"? I find delv bit difficult to use I always have to look up options again...

That was what I called it originally, but then it occurred to me that delv already has options +mtrace, +rtrace, and +vtrace (they turn on message logging, resolver logging, and validator logging, respectively) and I was concerned that +trace might be confusing. But you're right, +ns is going to be just as confusing for people who are familiar with dig +trace, so it's a matter of deciding between confusions.

(Or, ideally, going back in time and bopping that idiot past-Evan on the back of the head for not calling the options +mlog, +rlog and +vlog like a sensible person would've.)