[Gimp-developer] Bug reports on PhotoShop "adjustment layers" vs "layer styles"

[Elle Stone <ellestone ninedegreesbelow com>]

This bug report:

https://bugzilla.gnome.org/show_bug.cgi?id=79025
original Summary: Add support for Photoshop Styles
Summary modified to be: Add support for Photoshop Styles and adjustment 
layers

is marked as a duplicate of 13 other bug reports, including this bug report:

https://bugzilla.gnome.org/show_bug.cgi?id=98262
Summary: Adjustment Layers (like in Photoshop)

which has a comment that says PhotoShop layer styles and PhotoShop 
adjustment layers are "the same", which I take to mean that both could 
be implemented using substantially the same GEGL code.

Back when I used PhotoShop, I used the non-destructive "adjustment 
layers" 
(https://www.photoshopessentials.com/photo-editing/adjustment-layers/) - 
Curves, Levels, Channel Mixer, and such - all the time, with every 
single photograph I ever edited.

I think I used "layer styles" 
(https://helpx.adobe.com/photoshop/using/layer-effects-styles.html) only 
once during the entire time I used PhotoShop, as part of making a fancy 
logo for a website.

The applicable GIMP bug reports are quite old, dating as far back as 2002.

From the vantage point of "GEGL code in 2018", are the functionalities 
of PhotoShop "adjustment layers" and "layer styles" similar enough from 
an implementation point of view that both could be implemented all at 
once, using the same GEGL code? Or would there need to be substantially 
different/additional code for layer styles, compared to adjustment layers?

Best,
Elle