Your foam work looks amazing. Every time I try to do a foam build I can never make good cuts. always jaggedy ulgy messes, even with a xacto. Can't wait to see the undersuit
Take your time when doing the cuts. and make sure you have a sharp blade. just because its an x-acto doesnt mean its sharp.
What i did is went to walmart and bought a knife sharpener from the kitchen area and i use that to sharpen my blades every few pieces. maybe try that or try swapping out blades when you start to get the jagged cuts.