I made sure to run this through several times before posting. But a certain few sequences I have tried still are suffering from massive amounts of flicker no matter what I try to do.

I have the latest version with the latest Lightroom and it's still not producing the correct result.

I have been using LRTimelapse for years (I'm certainly no expert however) but there are still certain sequences that the Deflicker seems to have no or very little effect on.

What can you suggest to diminish the amount of flicker that I am experiencing in these sequences above the normal process?

The heavier you edit in Lightroom, the less effect will deflicker with LRT3 have, because it only analyses the original previews.
It would certainly help to help you, if you could post a screenshot of the LRTimelapse screen with the curves and preview.