Dayton bosses love that quick fix logic. The real time sink is always in the fixturing, not the tooling. Try a low-temp thermoplastic mold for those thin walls, it grips without the crush.

Yikes, my friend's turned into a cheesy brick too!

Had a similar wake-up call with woodworking finish. Skipped the sanding sealant once to save time, and the stain blotched so bad it looked like a toddler painted it. Now I never skip the prep steps, no matter how tedious they seem.