Custom Foam Insert Design

I need a straightforward design for a polyethylene foam insert that will sit inside a small box and keep a single, irregular-shaped fragile item safe during shipping. I can provide photos and basic measurements of the object; from there, I’m looking for a simple CAD layout (DXF, STEP, or similar) that I can use on Twotrees machine

Scope:
• One insert sized to my box dimensions
• Cut-out shaped precisely to the irregular object, with enough clearance for easy removal and snug protection
• Basic recommendations on foam thickness and durometer appropriate for polyethylene

I don’t need a full packaging system—just the insert drawing plus any notes a fabricator would expect (tolerances, layer order if multi-layered). Quick turnaround is appreciated, and experience with packaging or foam conversion tools like SolidWorks or Fusion 360 will help you finish this rapidly.