Gmic has a original layer mode "edge merging"

..here a little experiment
A ) Background Layer ( from my scraps )
Attachment:
temple.jpg [ 476.05 KiB | Viewed 5936 times ]
B ) Top Layer
Attachment:
pattern.png [ 621.7 KiB | Viewed 5936 times ]
A+B (mixed with Gmic/Layer/Edge Merging)
Attachment:
merged.jpg [ 504.27 KiB | Viewed 5936 times ]
As final image, i am not too happy
i would edit to eliminate or attenuate the effect at the top and here and there , to reveal more the temple...
but i want to show the exact merging result
The point of this layer mode is preserve and combine the edges of both images and seems doing well
(...As for the other Gmic layer modes there is not the opacity control

, but you may control the "smootness" of the FX.
PS For mods
i suppose this shoud be better in the plugin board, sorry