I think I can say this is resolved!  

I tried a quick test run indoors, by roughly increasing the shutter all in just M mode, and sure enough I get the HG Wizard! 

So I guess this means that with current versions of LRT (because as I said, in the past I've used the RamperPro method to switch without problems), a sequence that contains Bulb mode at any point will confuse LRT, or it means that there's something specific to the 1dxii that's causing this issue.  I'm REALLY curious to see if a 5dIV user with RamperPro has the same issue in LRT.  That would say for sure where the problem is.    

Either way, Manual mode it is!  This is somewhat relieving because anyone who's a Canon user and RamperPro user knows how awful it is to wait around for the switch to Bulb mode....

This post was last modified: 2017-02-23, 11:40 by Gunther.

The thing with bulb mode is, that every camera works differently in Bulb mode. Some cameras can so smooth time changes without steps, others only can do discrete times. Exif-Data will always be in discrete steps. So often the exif exposure time is not the same as the real exposure time. The same happens in A-Mode btw.

Since LRTimelapse cannot know, how the camera controls the times in B mode, and when it switched to B mode, it will not offer the Holy Grail Wizard for those sequences. If you have discrete steps like in your example at the beginning, the Holy Grail Wizard could work for that part. But then at the end the bulb mode switched to smooth time changes (you can see it from the smoother blue curve), but the exif data is still discrete. For this part the holy grail wizard would then introduce jumps instead of removing them.

With other cameras then canon, you'd not even get smooth changes in Bulb mode.

This hole bulb ramping causes a huge mess especially when combined with exposure ramping that's why I thoroughly advise to not using it.
From my experience I don't see a single advantage in using Bulb ramping (I've read your points above).

• Normally you never need longer exposures then 30sec for timelapse. For Astro everything faster then 30 secs (I only go until 20) in my opinion is too fast. With fast lenses and a decent sensor it's no problem to capture perfect astro landscapes and the intervals can be shorter so that the stars, clouds etc don't get too fast.
  
• The quality of a resulting sequence shot in exposure/iso/ap ramping is at least as good as with bulb ramping when you use LRTimelapses Holy Grail Wizard and Visual Deflicker.
  
• You have much more flexibility with exp/iso/ap ramping because you can freely switch between the parameters then when using bulb ramping.
  

But now, how to process your "mixed" sequence.
Just do your keyframe editing without the HG Wizard. Then use the Visual Deflicker on the sequence and do some Deflicker/Refine steps. This will smoothen everything out too, even if it takes a bit longer.