Looks awesome!What material did you go with for the 3D printed parts? I've been making functional parts from CF PETG and I see that's outside the engine bay but I'd still be worried about warpage where it touches the heat exchanger. Sooooo...
I would say minimal pressure loss compared to anywhere else. If the gvr4 ofh ports are on the filtered side, the only drop you'll see is from the filter itself.
It will physically bolt on just fine, but you have to block a few of the oil drain-back ports. I guess I need more info on what you were told would or wouldn't fit.