In the first image I used a Clip to hide the edges of the blurred cover shadow of the Mask. The issue is that in some shaded regions are not showing up correctly on the edges, no matter how much I extend that blurred shape outwards from the edge of the clip.

The second image depicts the visible seams that I have no clue how to fix. These elements also use a clipping shape of the whole mask, yet there is a lack of pixel bleeding there and it becomes painfully obvious when I add a background shadow.

I kind of found some small workarounds, as shown in the final image, but those include removing the background shadow all together and softening the front shadow as well to reduce the edge visibility!

Please give me some tips on how to solve this. I tried with mask as well, but I can not get a gradient to follow multiple curved patterns in a fluid motion! I know about mesh gradient as a solution but that is also very tedious to work with since I have to fiddle a lot with matching my general mask shape. Wish that mesh gradient would just form along side the shape of my mask automatically!

EDIT: seems the blurred clip edges only bug out visually in Inkscape, but when exported into PNG format they render correctly.

Then my final issue is with the white seem that pop up on the black shadow in the background (middle image)!