Review this old forum post. When I changed the position of my CT clamps - 90 degree angle to the wire and centered on the wiring, my results were better. Look at the charts. Review the complete forum thread/post to see other user’s comments.
As for the foam spacers, that would be difficult for the SENSE team to provide. There are just too many wire sizes and configurations. Also there is an issue with foam spacers being flammable. Flammable products are not allowed inside the breaker panel. I took a chance for myself since my spacers are small and I am familiar with the NEC codes and feel comfortable working inside my panel.
If you do make a change to your CT clamp positions, be aware that you might lose some of your current device detections. They will have to be re-discovered again. That might take more weeks or months.
These are decisions you will have to make for yourself. What are the goals / objectives you want from the SENSE product? I wanted to verify that my ‘total monthly wattage’ was being billed correctly by my energy provider. I am an engineer so I was looking for accuracy.
Extract your data from the WEB APP - before and after the change and chart it. That is the only way to know if a change was positive for you. Good Luck!