I'm sure you could ... but I very much doubt that you should. If the entire flow is lengthwise through one or a couple of 4-inch tubes, you have very little frontal surface area and it would clog very quickly.i wonder if i could get some acrylic cylinders 4" diameter and make tubes that i can place the porrett foam into. so i can retain the look and functionality of the rest of the sump.
Removing the entire support structure for socks would allow much more foam and much more frontal area; I don't think it would affect the function of the rest of the sump? Welded on? It's plastic; grab a saw.
As far as the "look" of the sump...I've never even considered that. Function and efficiency are all that matters in a sump, IMHO; how it looks doesn't concern me any more than the "look" of my lawnmower's underside or my compost heap behind the barn. Even if your tank is a display in your living room...the stand's second most important function, after supporting the tank properly, is to hide all that other stuff underneath.
Poret foam is sold in various PPI grades...Pores Per Inch. If I were limited to just one, my most-useful size would be 30ppm, but I will use 20 and even 10ppm for prefilters, etc.
If I am reading this correctly, and the compartment for foam is only 1 inch deep...I can't see that working out at all. My mech chamber contains at least a couple of 2-inch thick foam slabs and a single 1-inch coarser one...plus has several more inches of free space above those. I think that you need to either completely re-work the sump...or just forget the whole idea and stick with socks.