Chastity in vanilla life discussion

My transition is still moving along. Just to recap: my Wife/KH is mostly vanilla, but she dips into chastity play—I suspect it’s for me. We’ve been weaving FLR into our daily life anyway. I was self-locking for about a week and mentioned it; she said keep going but wanted me to remove the cage (using the vice mini) each night after chores were done, as part of her foot massage routine. After two days, she instructed me to leave it on, so I’ve been locked 24/7 for over a week now. She’s been somewhat relaxed with the keys, and I haven’t cheated. Last night, she told me to swap cages: unlocked me from the plastic one and put on the metal cage before going up in the morning, leaving the old one in the bathroom. I always shower early and head off for work without waking her; such a Goddess. Anyway, back to my point. As I locked into that metal cage (see profile pic), what is it about sliding onto that metal shell and securing it that gives such a sense of finality and security compared to the plastic one? Is it the tight base ring? The weight? Less sensation transfer to my cock? The internal lock? Or just the feeling of total devotion to my Goddess? I have to keep proving myself for her pleasure now, staying patient as she guides me down Her path toward my FLR fantasy.