Struggling with temporal consistency in Runway Gen-3 for product shots

I've been trying to nail down a consistent 10-second loop for a new perfume bottle using Runway Gen-3 Alpha. The individual frames look incredible, but once I stitch them together, the gold cap on the bottle shifts shape and size slightly every second. It’s subtle, but when you watch it on a 4K monitor, it’s super distracting and makes the product look like it’s glitching. I’ve tried locking the camera angle in the prompt and using the same seed value, but the morphing persists. I also experimented with using a reference image for every single frame, but that’s incredibly tedious and the motion still drifts. Has anyone managed to get stable object integrity for longer durations? I considered using Kling 1.6 because I’ve heard it holds objects better, but I’m worried the physics might be off for a floating liquid effect I want to add. Is there a specific prompting technique or post-processing workflow in After Effects that you all use to hide these temporal inconsistencies? I need this to look premium, not like a tech demo. If I have to switch tools, I’d rather start over now than render twenty bad takes. Any advice on maintaining rigid geometry for non-organic objects would be a lifesaver. I’m currently stuck on whether the issue is inherent to the model’s training data or if I’m just prompting the material properties wrong. I’d appreciate any insights from people who have done similar commercial work.