ok I found a work around for the User Interface.
Basically I am making a color dodge based on Transparency values.
To use this with the UE4 color dodge blend, first I had to replace all the transparent data with black background which essentially makes no color dodge . I did this in UE4 by inverting my alpha channel then Lerp’ing to black.
After applying the color dodge it has a very strange effect without any alpha information, but at least it is color dodging correctly.
To fix this, I then Lerp’ed to my original background using the alpha of my intended color dodge image, and voila. Works as expected.
(minus the intensity not being as much as I expected, but this could be due to some differences in how I made my menu animation in photoshop versus Unreal; I unfortunately am lacking some workarounds for the photoshop Adjustment layers still)
This is the color dodge texture I am using:
