And, of course, I had to revisit that old proof-of-concept on the U.S. laserdisc edition of THX 1138 -- now that I'm getting the hang of DeHalo_alpha settings. Back then, I max'ed it out to wipe the edge enhancement entirely (it can't -- the author described it as a "trick" function). Now, after a feel for what the numbers are doing and a minimum setting just enough to show improvement, all the unsightly edge-peaking is nicely diminished. It turns out that the only setting away from the defaults was to "turn off" (0.0) dark-edge processing, to operate only on the over-bright edges:
This is the only line of code (along with the already posted DeHalo_alpha script) to do the job:
video_DH = video.ConvertToYV12().DeHalo_alpha( darkstr=0.0 ).ConvertToRGB32()