ETTR settings for holy grail timelapse

[fauxtoejoe]

I've been loving  auto ETTR  for shooting time lapses where I can't be near the camera to manually adjust exposure during the holy grail transitions. I am consistently having one problem though:
Instead of continuously slowing the shutter speed as the light fades, it toggles back and forth before settling in on the next slowest shutter speed. This creates a ton of keyframes in LR Timelapse which I then have to manually adjust. It seems to do this without much reason- no clouds passing shadows or object moving into frame to change exposure. Would boosting the 'highlight ignore' help ML stick with its decision?
There must be a way to set the AETTR so that it adjusts exposure less frequently, but in larger steps. (and in only one direction)
Thanks for any suggestions.

[ansius]

AS much as I understand (correct me if I'm wrong) that this fluctuation is caused by the optimal setting not being available thus camera oscillates in between two neighboring ones, this happens also in regular camera auto / semi-auto modes. Unless you don't overexpose anything this has no visual consequences, you have to be careful with sun tough, because the overblown disk size would oscillate and that is not that easy to fix later, even tough the exposure is. For example, de-flickering with the adobe bridge script http://www.magiclantern.fm/forum/index.php?topic=8850.0, is easy and when care taken - gives awesome results, so I have stick to that despite some other methods being faster or more user friendly like the LR time lapse