I strongly recommend to travel to a boutique because you have to feel and decide for yourself if it's worth it to you and which one you prefer on your wrist. We can give you advise, which we already did in the previous thread and other posts, but at the end only you know were your heart is and what you like most.
The small is lightweight yes, but the small JUC will not just break. If that would really happen without abusing it, I'm sure Cartier would take care of it.
Leaning on your arm will not crush it. Many people have this JUC and enjoy it while others prefer the regular. That's a personal choice only you can make.
If you want a thicker, solid bracelet, go for the regular. If you like a very dainty look, take the small. Or take both, one small with diamonds and one regular without if you really love both.
But only if you are 100% sure. Way too much money to be not sure.
And if you really can't visit a boutique, perhaps you can order a small online and see if it works for you? You can always return (but be careful for not scratching it when you try it on) if it doesn't work for you. I think that would be the best way to find out if the small works for you or not if you can't go to the boutique. Otherwise you keep doubting, you only know for sure how you feel about it when you try it on and when you can see it on your wrist. Take pictures of it when you need to, maybe that will also help with your decision, good luck!