Yeah, looks like Luma Waves gets a bit confused when it receives a texture input that is not 4:3. You can already see it just in a regular 16:9 comp applied on 16:9 content.
It's definitely not how it's supposed to be, and I'll make a ticket, but I'm not sure if we can spend too much time on this. Especially seeing how you're the first one to mention this in over 8 years, fixing it might break it for someone else. Luma Waves is generally meant to create a extruded 3d look like you get in the Landscape preset, and not really meant as a pixelation filter.
Had to take care of all
lumawaves and
pixels in space
If input comes from
layer1 the FX get sized correct.
If input comes from
layer2 the FX get cut. (There are missing parts of the fx, wich cant be adjusted)
There was no way to bring it in line with the FX generated from Layer1 by adjusting the clip or layer settings.