The following comments were made before LRHazeFilters was developed. I am leaving them as a record of why the direct, realtime updating of values in filters does not work.
The Lightroom CC update released at the same time as Lightroom 6.1 introduced the Dehaze adjustment and also added local Whites and Blacks adjustments to the Gradient Filter, Radial Filter and Local adjustment brush.
I looked at the possibility of creating a similar plug-in to LRHaze to support the new local Whites and Blacks adjustments, but it appears that these settings are blocked in Lightroom 6.1.
In Lightroom SDK terms: LrDevelopController.getValue(“local_Whites2012”) always returns nil in Lightroom 6.1.
With the introduction of local Dehaze in Lightroom 6.2, I again looked to see if it could be used, but again found that access is blocked.
In Lightroom SDK terms: LrDevelopController.getValue(“local_Dehaze”) always returns nil in Lightroom 6.2.
You can draw your own conclusions about the fact that LRHaze works. It might be by design or it might be that there is a bug or oversight in Lightroom 6.1 that lets it work at present. If it is a bug and the bug gets ‘fixed’ in the future, LRHaze may stop working.