I set up a separate servo for the nosewheel, and make one of the rotary knobs on the 14mz the primary control for the nosewheel servo.

Then set up two PMIXes from rudder to nosewheel, one is on all the time, and maybe 30-40% travel, the other one turns on below 1/3 throttle and is 60-70% travel.

Now you have full nosewheel authority for tight turns while taxiing, and much less twitchiness while taking off. And the knob provides a nice way to rapidly adjust center on the nosewheel. On this TX you can push in the rotary knobs so they don't protrude and get bumped if you want to.

The "lots of expo" idea also sounds very good, and has the advantage of extreme simplicity :-)

I don't worry about disabling the nosewheel servo in flight because of the slack cables, as mentioned above, though it would be quite simple to set up...

Dave