I wore my LOVE and JUC (both size 17) stacked for three weeks until I couldn’t bear the overlapping and scratches (horizontal lines running across the top of my LOVE). After that, my JUC came off and was only worn occasionally.
If you need a spacer, I would recommend wearing an Invisibobble between the two pieces (saw this on another person in one of the Cartier threads - thank you!) OR you will need to wear the JUC on your other wrist. That’s what I do now (since June 2021) because my JUC sat unworn for years (purchased in 2014) and it made me sad especially because my partner and I bought each other one as a gift.
It took me about 5 days to get used to wearing it solo (it’s quite weighty!) but I find separating the pieces allows you to appreciate the craftsmanship and beauty of each piece (whilst minimising the damage caused by overlapping). I’ve had my LOVE for 10 years now and it has never come off.