I do believe the neck is straighter and flatter than it was. The trouble is that the rim of the resonator still intrudes on practical action height, and I still get buzzing up the neck.
There are things I can try, both in the realm of the minor tweak and the substantial change, to remedy this. One thing I might try is tightening the drum head more significantly, and/or substituting a taller bridge. (I suppose it's also possible to reduce the neck angle and go for a shorter bridge, and see if that works.) I could also simply relieve wood from the resonator rim, which seems like a gruesome change, but would be worth it if it works.
On the plus side, the action (at least below the octave) is better than it was, and I got the chance to restring the fifth string so that the cut end is not at substantial risk of putting a hole in my thumb during normal playing. I did end up going with a fifths tuning this time, to wit:
- 5th: 09p, tuned G4
- 4th: 32w, tuned G2
- 3rd: 26w, tuned D3
- 2nd: 18p, tuned A3
- 1st: 12p, tuned E4
Next steps: play this a little bit, mostly below the octave to stay away from the buzzing, and contemplate this "steeper neck, taller bridge, shallower nut" or "shallower neck, shorter bridge, deeper nut" question. Learn more about the right hand.
It's a tinkerer's project anyway. So, tinker.